diff --git a/CHANGELOG.md b/CHANGELOG.md
index e22222388..f03fb239f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,11 +2,12 @@
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## Unreleased
+## Version [v0.1.15] - 2025-08-29
 
 ### Fixed
 
 * Top-level `.juliabundleignore` files are now correctly handled when using `JuliaHub.appbundle`. ([#99], [#100])
+* The `JuliaHub.upload_dataset` now correctly throws a `JuliaHubError` on certain backend errors. ([#103])
 
 ## Version [v0.1.14] - 2025-06-11
 
@@ -159,6 +160,7 @@ Initial package release.
 [v0.1.12]: https://github.com/JuliaComputing/JuliaHub.jl/releases/tag/v0.1.12
 [v0.1.13]: https://github.com/JuliaComputing/JuliaHub.jl/releases/tag/v0.1.13
 [v0.1.14]: https://github.com/JuliaComputing/JuliaHub.jl/releases/tag/v0.1.14
+[v0.1.15]: https://github.com/JuliaComputing/JuliaHub.jl/releases/tag/v0.1.15
 [#1]: https://github.com/JuliaComputing/JuliaHub.jl/issues/1
 [#2]: https://github.com/JuliaComputing/JuliaHub.jl/issues/2
 [#3]: https://github.com/JuliaComputing/JuliaHub.jl/issues/3
@@ -194,3 +196,4 @@ Initial package release.
 [#96]: https://github.com/JuliaComputing/JuliaHub.jl/issues/96
 [#99]: https://github.com/JuliaComputing/JuliaHub.jl/issues/99
 [#100]: https://github.com/JuliaComputing/JuliaHub.jl/issues/100
+[#103]: https://github.com/JuliaComputing/JuliaHub.jl/issues/103
diff --git a/Project.toml b/Project.toml
index 49cad18bc..926b3a71c 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "JuliaHub"
 uuid = "bc7fa6ce-b75e-4d60-89ad-56c957190b6e"
 authors = ["JuliaHub Inc."]
-version = "0.1.14"
+version = "0.1.15"
 
 [deps]
 Base64 = "2a0f44e3-6c83-55bd-87e4-b1978d98bd5f"
diff --git a/src/datasets.jl b/src/datasets.jl
index 9b98dc9d1..08be8b274 100644
--- a/src/datasets.jl
+++ b/src/datasets.jl
@@ -793,7 +793,9 @@ function _new_dataset(
 end
 
 function _open_dataset_version(auth::Authentication, name::AbstractString)::_RESTResponse
-    _restcall(auth, :POST, "user", "datasets", name, "versions")
+    r = _restcall(auth, :POST, "user", "datasets", name, "versions")
+    _check_internal_error(r; var="POST /user/datasets/{name}/versions")
+    return r
 end
 
 function _upload_dataset(upload_config, local_path; progress::Bool)
diff --git a/src/projects.jl b/src/projects.jl
index 903d06165..08ffa355f 100644
--- a/src/projects.jl
+++ b/src/projects.jl
@@ -282,12 +282,14 @@ function _open_dataset_version(
     auth::Authentication, dataset_uuid::UUID, project_uuid::UUID
 )::_RESTResponse
     body = Dict("project" => string(project_uuid))
-    return JuliaHub._restcall(
+    r = JuliaHub._restcall(
         auth,
         :POST,
         ("datasets", string(dataset_uuid), "versions"),
         JSON.json(body),
     )
+    _check_internal_error(r; var="POST /user/datasets/{name}/versions")
+    return r
 end
 
 function _close_dataset_version(
diff --git a/src/restapi.jl b/src/restapi.jl
index c44660ffd..5ebdb854c 100644
--- a/src/restapi.jl
+++ b/src/restapi.jl
@@ -79,6 +79,31 @@ function _parse_response_json(r::_RESTResponse, ::Type{T})::Tuple{T, String} whe
     return _parse_response_json(r.body, T)
 end
 
+# Check that the API response is not a legacy 200 internal error, where
+# we return
+#
+# {"success": false, "interal_error": true, "message": "..."}
+#
+# on internal errors. If it detects that this is an internal error, it throws
+# a JuliaHubError. Returns `nothing` otherwise.
+function _check_internal_error(r::_RESTResponse; var::AbstractString)
+    if !(r.status == 200)
+        return nothing
+    end
+    success = _get_json_or(r.json, "success", Any, nothing)
+    internal_error = _get_json_or(r.json, "internal_error", Any, nothing)
+    if (success === false) && (internal_error === true)
+        e = JuliaHubError(
+            """
+            Internal Server Error 200 response from JuliaHub ($var):
+            JSON: $(sprint(show, MIME("text/plain"), r.json))
+            """,
+        )
+        throw(e)
+    end
+    return nothing
+end
+
 # _restcall calls _rest_request_mockable which calls _rest_request_http. The reason for this
 # indirection is that the signature of _rest_request_mockable is extremely simple and therefore
 # each to hook into with Mockable.
diff --git a/test/datasets.jl b/test/datasets.jl
index 4e3ff821e..f382ef23f 100644
--- a/test/datasets.jl
+++ b/test/datasets.jl
@@ -435,6 +435,15 @@ end
         @test_throws TypeError JuliaHub.upload_dataset(
             "example-dataset-license", @__FILE__; replace=true, license=(:fulltext, 1234)
         )
+
+        # Make sure we throw a JuliaHubError when we encounter an internal backend error
+        # that gets reported over a 200.
+        @test JuliaHub.upload_dataset("example-dataset-200-error-1", @__FILE__) isa JuliaHub.Dataset
+        MOCK_JULIAHUB_STATE[:internal_error_200] = true
+        @test_throws JuliaHub.JuliaHubError JuliaHub.upload_dataset(
+            "example-dataset-200-error", @__FILE__
+        )
+        MOCK_JULIAHUB_STATE[:internal_error_200] = false
     end
     empty!(MOCK_JULIAHUB_STATE)
 end
diff --git a/test/mocking.jl b/test/mocking.jl
index 6a7a54ebf..794a33cb0 100644
--- a/test/mocking.jl
+++ b/test/mocking.jl
@@ -46,6 +46,14 @@ JuliaHub.__AUTH__[] = DEFAULT_GLOBAL_MOCK_AUTH
 Mocking.activate()
 const MOCK_JULIAHUB_STATE = Dict{Symbol, Any}()
 jsonresponse(status) = d -> JuliaHub._RESTResponse(status, JSON.json(d))
+function internal_error_200_response()
+    d = Dict(
+        "success" => false,
+        "internal_error" => true,
+        "message" => "Internal Server Error",
+    )
+    return JuliaHub._RESTResponse(200, JSON.json(d))
+end
 mocking_patch = [
     Mocking.@patch(
         JuliaHub._rest_request_mockable(args...; kwargs...) = _restcall_mocked(args...; kwargs...)
@@ -412,6 +420,9 @@ function _restcall_mocked(method, url, headers, payload; query)
             Dict("repo_id" => string(UUIDs.uuid4())) |> jsonresponse(200)
         end
     elseif (method == :POST) && endswith(url, DATASET_VERSIONS_REGEX)
+        if get(MOCK_JULIAHUB_STATE, :internal_error_200, false)
+            return internal_error_200_response()
+        end
         dataset, is_user = let m = match(DATASET_VERSIONS_REGEX, url)
             URIs.unescapeuri(m[2]), m[1] == "user/"
         end
diff --git a/test/projects.jl b/test/projects.jl
index 4c3985f3a..346b076ac 100644
--- a/test/projects.jl
+++ b/test/projects.jl
@@ -243,6 +243,12 @@ end
         @test dataset.project.uuid === project_auth_2.project_id
         @test dataset.project.is_writable === false
         @test JuliaHub.upload_project_dataset(dataset_noproject, @__FILE__) isa JuliaHub.Dataset
+
+        MOCK_JULIAHUB_STATE[:internal_error_200] = true
+        @test_throws JuliaHub.JuliaHubError JuliaHub.upload_project_dataset(
+            dataset_noproject, @__FILE__
+        )
+        MOCK_JULIAHUB_STATE[:internal_error_200] = false
     end
 end