diff --git a/lib/archethic/contracts.ex b/lib/archethic/contracts.ex
index 4597684b2..e523c770a 100644
--- a/lib/archethic/contracts.ex
+++ b/lib/archethic/contracts.ex
@@ -51,9 +51,7 @@ defmodule Archethic.Contracts do
           nil | Transaction.t(),
           nil | Recipient.t(),
           Keyword.t()
-        ) ::
-          {:ok, nil | Transaction.t()}
-          | {:error, :contract_failure | :invalid_triggers_execution}
+        ) :: {:ok, nil | Transaction.t()} | {:error, String.t()}
   defdelegate execute_trigger(
                 trigger_type,
                 contract,
diff --git a/lib/archethic/contracts/interpreter.ex b/lib/archethic/contracts/interpreter.ex
index 97834a39e..657490df6 100644
--- a/lib/archethic/contracts/interpreter.ex
+++ b/lib/archethic/contracts/interpreter.ex
@@ -126,7 +126,7 @@ defmodule Archethic.Contracts.Interpreter do
           execute_opts()
         ) ::
           {:ok, nil | Transaction.t()}
-          | {:error, :contract_failure | :invalid_triggers_execution}
+          | {:error, String.t()}
   def execute_trigger(
         trigger_key,
         %Contract{
@@ -141,7 +141,7 @@ defmodule Archethic.Contracts.Interpreter do
       ) do
     case Map.get(triggers, trigger_key) do
       nil ->
-        {:error, :invalid_triggers_execution}
+        {:error, "Trigger not found on the contract"}
 
       %{args: args, ast: trigger_code} ->
         timestamp_now =
@@ -183,9 +183,7 @@ defmodule Archethic.Contracts.Interpreter do
     end
   rescue
     err ->
-      Logger.error(Exception.format(:error, err, __STACKTRACE__))
-      # it's ok to loose the error because it's user-code
-      {:error, :contract_failure}
+      {:error, error_to_string(err, __STACKTRACE__)}
   end
 
   @doc """
@@ -503,4 +501,20 @@ defmodule Archethic.Contracts.Interpreter do
       end
     end
   end
+
+  defp error_to_string(err, stacktrace) do
+    case Enum.find_value(stacktrace, fn
+           {_, _, _, [file: 'nofile', line: line]} ->
+             line
+
+           _ ->
+             false
+         end) do
+      line when is_integer(line) ->
+        Exception.message(err) <> " - L#{line}"
+
+      _ ->
+        Exception.message(err)
+    end
+  end
 end
diff --git a/lib/archethic/contracts/interpreter/common_interpreter.ex b/lib/archethic/contracts/interpreter/common_interpreter.ex
index 6a010467f..efda02909 100644
--- a/lib/archethic/contracts/interpreter/common_interpreter.ex
+++ b/lib/archethic/contracts/interpreter/common_interpreter.ex
@@ -152,11 +152,11 @@ defmodule Archethic.Contracts.Interpreter.CommonInterpreter do
   # whitelist assignation & write them to scope
   # this is done in the prewalk because it must be done before the "variable are read from scope" step
   def prewalk(
-        _node = {:=, _, [{{:atom, var_name}, _, nil}, value]},
+        _node = {:=, meta, [{{:atom, var_name}, _, nil}, value]},
         acc
       ) do
     new_node =
-      quote do
+      quote line: Keyword.fetch!(meta, :line) do
         Scope.write_cascade(unquote(var_name), unquote(value))
       end
 
@@ -167,9 +167,12 @@ defmodule Archethic.Contracts.Interpreter.CommonInterpreter do
   end
 
   # Dot access non-nested (x.y)
-  def prewalk(_node = {{:., _, [{{:atom, map_name}, _, nil}, {:atom, key_name}]}, _, _}, acc) do
+  def prewalk(
+        _node = {{:., meta, [{{:atom, map_name}, _, nil}, {:atom, key_name}]}, _, _},
+        acc
+      ) do
     new_node =
-      quote do
+      quote line: Keyword.fetch!(meta, :line) do
         Scope.read(unquote(map_name), unquote(key_name))
       end
 
@@ -178,9 +181,9 @@ defmodule Archethic.Contracts.Interpreter.CommonInterpreter do
 
   # Dot access nested (x.y.z)
   # or Module.function().z
-  def prewalk({{:., _, [first_arg, {:atom, key_name}]}, _, []}, acc) do
+  def prewalk({{:., meta, [first_arg, {:atom, key_name}]}, _, []}, acc) do
     new_node =
-      quote do
+      quote line: Keyword.fetch!(meta, :line) do
         Map.get(unquote(first_arg), unquote(key_name))
       end
 
@@ -189,12 +192,12 @@ defmodule Archethic.Contracts.Interpreter.CommonInterpreter do
 
   # Map access non-nested (x[y])
   def prewalk(
-        _node = {{:., _, [Access, :get]}, _, [{{:atom, map_name}, _, nil}, accessor]},
+        _node = {{:., meta, [Access, :get]}, _, [{{:atom, map_name}, _, nil}, accessor]},
         acc
       ) do
     # accessor can be a variable, a function call, a dot access, a string
     new_node =
-      quote do
+      quote line: Keyword.fetch!(meta, :line) do
         Scope.read(unquote(map_name), unquote(accessor))
       end
 
@@ -203,11 +206,11 @@ defmodule Archethic.Contracts.Interpreter.CommonInterpreter do
 
   # Map access nested (x[y][z])
   def prewalk(
-        _node = {{:., _, [Access, :get]}, _, [first_arg, accessor]},
+        _node = {{:., meta, [Access, :get]}, _, [first_arg, accessor]},
         acc
       ) do
     new_node =
-      quote do
+      quote line: Keyword.fetch!(meta, :line) do
         Map.get(unquote(first_arg), unquote(accessor))
       end
 
@@ -244,8 +247,12 @@ defmodule Archethic.Contracts.Interpreter.CommonInterpreter do
   # log (not documented, only useful for developer debugging)
   # TODO: should be implemented in a module Logger (only available if config allows it)
   # will soon be updated to log into the playground console
-  def prewalk(_node = {{:atom, "log"}, _, [data]}, acc) do
-    new_node = quote do: apply(IO, :inspect, [unquote(data)])
+  def prewalk(_node = {{:atom, "log"}, meta, [data]}, acc) do
+    new_node =
+      quote line: Keyword.fetch!(meta, :line) do
+        apply(IO, :inspect, [unquote(data)])
+      end
+
     {new_node, acc}
   end
 
@@ -274,20 +281,21 @@ defmodule Archethic.Contracts.Interpreter.CommonInterpreter do
   # ----------------------------------------------------------------------
   # exit block == set parent scope
   # we need to return user's last expression and not the result of Scope.leave_scope()
+  # ps: there is no meta in a :__block__
   def postwalk(
-        _node = {:__block__, meta, expressions},
+        _node = {:__block__, [], expressions},
         acc
       ) do
     {last_expression, expressions} = List.pop_at(expressions, -1)
 
-    {:__block__, _meta, new_expressions} =
+    {:__block__, [], new_expressions} =
       quote do
         result = unquote(last_expression)
         Scope.leave_scope()
         result
       end
 
-    {{:__block__, meta, expressions ++ new_expressions}, acc}
+    {{:__block__, [], expressions ++ new_expressions}, acc}
   end
 
   # Module function call
@@ -307,7 +315,7 @@ defmodule Archethic.Contracts.Interpreter.CommonInterpreter do
 
     new_node =
       if Library.function_tagged_with?(module_name, function_name, :write_contract) do
-        quote do
+        quote line: Keyword.fetch!(meta, :line) do
           # mark the next_tx as dirty
           Scope.update_global([:next_transaction_changed], fn _ -> true end)
 
@@ -328,11 +336,11 @@ defmodule Archethic.Contracts.Interpreter.CommonInterpreter do
 
   # variable are read from scope
   def postwalk(
-        _node = {{:atom, var_name}, _, nil},
+        _node = {{:atom, var_name}, meta, nil},
         acc
       ) do
     new_node =
-      quote do
+      quote line: Keyword.fetch!(meta, :line) do
         Scope.read(unquote(var_name))
       end
 
@@ -342,7 +350,7 @@ defmodule Archethic.Contracts.Interpreter.CommonInterpreter do
   # for var in list
   def postwalk(
         _node =
-          {{:atom, "for"}, _,
+          {{:atom, "for"}, meta,
            [
              {:%{}, _, [{var_name, list}]},
              [do: block]
@@ -356,7 +364,7 @@ defmodule Archethic.Contracts.Interpreter.CommonInterpreter do
     # transform the for-loop into Enum.each
     # and create a variable in the scope
     new_node =
-      quote do
+      quote line: Keyword.fetch!(meta, :line) do
         Enum.each(unquote(list), fn x ->
           Scope.write_at(unquote(var_name), x)
 
@@ -367,9 +375,9 @@ defmodule Archethic.Contracts.Interpreter.CommonInterpreter do
     {new_node, acc}
   end
 
-  def postwalk({{:atom, function_name}, _, args}, acc) when is_list(args) do
+  def postwalk({{:atom, function_name}, meta, args}, acc) when is_list(args) do
     new_node =
-      quote do
+      quote line: Keyword.fetch!(meta, :line) do
         Scope.execute_function_ast(unquote(function_name), unquote(args))
       end
 
@@ -377,7 +385,8 @@ defmodule Archethic.Contracts.Interpreter.CommonInterpreter do
   end
 
   # BigInt mathematics to avoid floating point issues
-  def postwalk(_node = {ast, meta, [lhs, rhs]}, acc) when ast in [:*, :/, :+, :-] do
+  def postwalk(_node = {ast, meta, [lhs, rhs]}, acc)
+      when ast in [:*, :/, :+, :-] do
     new_node =
       quote line: Keyword.fetch!(meta, :line) do
         AST.decimal_arithmetic(unquote(ast), unquote(lhs), unquote(rhs))
diff --git a/lib/archethic/contracts/interpreter/library/common/http_impl.ex b/lib/archethic/contracts/interpreter/library/common/http_impl.ex
index c4ca8acdf..6c3d4e46e 100644
--- a/lib/archethic/contracts/interpreter/library/common/http_impl.ex
+++ b/lib/archethic/contracts/interpreter/library/common/http_impl.ex
@@ -38,6 +38,9 @@ defmodule Archethic.Contracts.Interpreter.Library.Common.HttpImpl do
       {:ok, {:error, :threshold_reached}} ->
         raise Library.Error, message: "Http.fetch/1 response is bigger than threshold"
 
+      {:ok, {:error, :not_https}} ->
+        raise Library.Error, message: "Http.fetch/1 was called with a non https url"
+
       {:ok, {:error, _}} ->
         # Mint.HTTP.connect error
         # Mint.HTTP.stream error
@@ -49,7 +52,7 @@ defmodule Archethic.Contracts.Interpreter.Library.Common.HttpImpl do
 
       nil ->
         # Task.shutdown
-        raise Library.Error, message: "Http.fetch/1 timed out for url: #{uri}"
+        raise Library.Error, message: "Http.fetch/1 timed out"
     end
   end
 
@@ -87,6 +90,10 @@ defmodule Archethic.Contracts.Interpreter.Library.Common.HttpImpl do
           raise Library.Error,
             message: "Http.fetch_many/1 response is bigger than threshold for url: #{uri}"
 
+        {{:ok, {:error, :not_https}}, uri}, _ ->
+          raise Library.Error,
+            message: "Http.fetch_many/1 was called with a non https url: #{uri}"
+
         {{:ok, {:error, _}}, uri}, _ ->
           # Mint.HTTP.connect error
           # Mint.HTTP.stream error
diff --git a/lib/archethic_web/api/jsonrpc/error.ex b/lib/archethic_web/api/jsonrpc/error.ex
index f15ca3347..4bc24fde9 100644
--- a/lib/archethic_web/api/jsonrpc/error.ex
+++ b/lib/archethic_web/api/jsonrpc/error.ex
@@ -37,7 +37,6 @@ defmodule ArchethicWeb.API.JsonRPC.Error do
   # Smart Contract context
   defp get_custom_code(:contract_failure), do: 203
   defp get_custom_code(:no_recipients), do: 204
-  defp get_custom_code(:invalid_triggers_execution), do: 205
   defp get_custom_code(:invalid_transaction_constraints), do: 206
   defp get_custom_code(:invalid_inherit_constraints), do: 207
   defp get_custom_code(:parsing_contract), do: 208
diff --git a/lib/archethic_web/api/jsonrpc/methods/simulate_contract_execution.ex b/lib/archethic_web/api/jsonrpc/methods/simulate_contract_execution.ex
index 4e17cb319..1d30306f9 100644
--- a/lib/archethic_web/api/jsonrpc/methods/simulate_contract_execution.ex
+++ b/lib/archethic_web/api/jsonrpc/methods/simulate_contract_execution.ex
@@ -78,14 +78,34 @@ defmodule ArchethicWeb.API.JsonRPC.Method.SimulateContractExecution do
        ) do
     with {:ok, contract_tx} <-
            Archethic.get_last_transaction(recipient_address),
-         {:ok, contract} <- Contracts.from_transaction(contract_tx),
+         {:ok, contract} <- validate_and_parse_contract_tx(contract_tx),
          trigger <- Contract.get_trigger_for_recipient(recipient),
          :ok <- validate_contract_condition(trigger, contract, trigger_tx, recipient, timestamp),
-         {:ok, next_tx} <- Contracts.execute_trigger(trigger, contract, trigger_tx, recipient) do
+         {:ok, next_tx} <- validate_and_execute_trigger(trigger, contract, trigger_tx, recipient) do
       validate_contract_condition(:inherit, contract, next_tx, nil, timestamp)
     end
   end
 
+  defp validate_and_parse_contract_tx(tx) do
+    case Contracts.from_transaction(tx) do
+      {:ok, contract} ->
+        {:ok, contract}
+
+      {:error, reason} ->
+        {:error, {:parsing_error, reason}}
+    end
+  end
+
+  def validate_and_execute_trigger(trigger, contract, trigger_tx, recipient) do
+    case Contracts.execute_trigger(trigger, contract, trigger_tx, recipient) do
+      {:ok, nil_or_next_tex} ->
+        {:ok, nil_or_next_tex}
+
+      {:error, reason} ->
+        {:error, {:execute_error, reason}}
+    end
+  end
+
   defp create_valid_response(%Recipient{address: recipient_address}) do
     %{"recipient_address" => Base.encode16(recipient_address), "valid" => true}
   end
@@ -107,14 +127,6 @@ defmodule ArchethicWeb.API.JsonRPC.Method.SimulateContractExecution do
   defp format_reason(:network_issue),
     do: {:internal_error, "Cannot fetch contract transaction"}
 
-  defp format_reason(:contract_failure),
-    do: {:custom_error, :contract_failure, "Contract execution encountered an error"}
-
-  defp format_reason(:invalid_triggers_execution),
-    do:
-      {:custom_error, :invalid_triggers_execution,
-       "Contract does not contain a trigger transaction"}
-
   defp format_reason(:invalid_transaction_constraints),
     do:
       {:custom_error, :invalid_transaction_constraints,
@@ -128,9 +140,12 @@ defmodule ArchethicWeb.API.JsonRPC.Method.SimulateContractExecution do
   defp format_reason(:timeout),
     do: {:internal_error, "Timeout while simulating contract execution"}
 
-  defp format_reason(reason) when is_binary(reason),
+  defp format_reason({:parsing_error, reason}) when is_binary(reason),
     do: {:custom_error, :parsing_contract, "Error while parsing contract", reason}
 
+  defp format_reason({:execute_error, reason}) when is_binary(reason),
+    do: {:custom_error, :contract_failure, "Error while executing contract", reason}
+
   defp format_reason(_), do: {:internal_error, "Unknown error"}
 
   defp validate_contract_condition(condition_type, contract, tx, recipient, timestamp) do
diff --git a/lib/archethic_web/api/rest/controllers/transaction_controller.ex b/lib/archethic_web/api/rest/controllers/transaction_controller.ex
index 451ee5af9..5547ce4aa 100644
--- a/lib/archethic_web/api/rest/controllers/transaction_controller.ex
+++ b/lib/archethic_web/api/rest/controllers/transaction_controller.ex
@@ -248,22 +248,6 @@ defmodule ArchethicWeb.API.REST.TransactionController do
         {:error, "Network issue, please try again later."}
 
       # execute_contract errors
-      {:error, :contract_failure} ->
-        {:error, "Contract execution produced an error."}
-
-      {:error, :invalid_triggers_execution} ->
-        {:error, "Contract does not have a `actions triggered_by: transaction` block."}
-
-      {:error, :invalid_transaction_constraints} ->
-        {:error,
-         "Contract refused incoming transaction. Check the `condition transaction` block."}
-
-      {:error, :invalid_oracle_constraints} ->
-        {:error, "Contract refused incoming transaction. Check the `condition oracle` block."}
-
-      {:error, :invalid_inherit_constraints} ->
-        {:error, "Contract refused outcoming transaction. Check the `condition inherit` block."}
-
       # parse_contract errors
       {:error, reason} when is_binary(reason) ->
         {:error, reason}
diff --git a/test/archethic/contracts/interpreter_test.exs b/test/archethic/contracts/interpreter_test.exs
index c7efdad8b..0389d922b 100644
--- a/test/archethic/contracts/interpreter_test.exs
+++ b/test/archethic/contracts/interpreter_test.exs
@@ -656,6 +656,32 @@ defmodule Archethic.Contracts.InterpreterTest do
                )
     end
 
+    test "should return the proper line in case of error" do
+      code = """
+        @version 1
+        condition triggered_by: transaction, as: []
+        actions triggered_by: transaction do
+          div_by_zero()
+        end
+
+        export fun div_by_zero() do
+          1 / 0
+        end
+      """
+
+      contract_tx = ContractFactory.create_valid_contract_tx(code)
+
+      incoming_tx = TransactionFactory.create_valid_transaction([])
+
+      assert {:error, "division_by_zero - L8"} =
+               Interpreter.execute_trigger(
+                 {:transaction, nil, nil},
+                 Contract.from_transaction!(contract_tx),
+                 incoming_tx,
+                 nil
+               )
+    end
+
     test "should return nil when the contract is correct but no Contract.* call" do
       code = """
         @version 1
@@ -680,7 +706,7 @@ defmodule Archethic.Contracts.InterpreterTest do
                )
     end
 
-    test "should return contract_failure if contract code crash" do
+    test "should return an error if contract code crash" do
       code = """
         @version 1
         condition triggered_by: transaction, as: []
@@ -696,7 +722,7 @@ defmodule Archethic.Contracts.InterpreterTest do
       incoming_tx = TransactionFactory.create_valid_transaction([])
 
       assert match?(
-               {:error, :contract_failure},
+               {:error, "division_by_zero - L5"},
                Interpreter.execute_trigger(
                  {:transaction, nil, nil},
                  Contract.from_transaction!(contract_tx),
@@ -717,7 +743,7 @@ defmodule Archethic.Contracts.InterpreterTest do
       contract_tx = ContractFactory.create_valid_contract_tx(code)
 
       assert match?(
-               {:error, :contract_failure},
+               {:error, "Contract used add_uco_transfer with an invalid amount - L5"},
                Interpreter.execute_trigger(
                  {:transaction, nil, nil},
                  Contract.from_transaction!(contract_tx),
diff --git a/test/archethic_web/api/jsonrpc/error_test.exs b/test/archethic_web/api/jsonrpc/error_test.exs
index 3c34be614..b97c72039 100644
--- a/test/archethic_web/api/jsonrpc/error_test.exs
+++ b/test/archethic_web/api/jsonrpc/error_test.exs
@@ -32,7 +32,6 @@ defmodule ArchethicWeb.API.JsonRPC.ErrorTest do
     test "should return custom error code for smart contract context" do
       assert %{"code" => 203} = Error.get_error({:custom_error, :contract_failure, ""})
       assert %{"code" => 204} = Error.get_error({:custom_error, :no_recipients, ""})
-      assert %{"code" => 205} = Error.get_error({:custom_error, :invalid_triggers_execution, ""})
 
       assert %{"code" => 206} =
                Error.get_error({:custom_error, :invalid_transaction_constraints, ""})