diff --git a/tidy3d/__init__.py b/tidy3d/__init__.py
index b7804d3744..9c049c2bf4 100644
--- a/tidy3d/__init__.py
+++ b/tidy3d/__init__.py
@@ -63,4 +63,4 @@
 
 # make all stdout and errors pretty
 pretty.install()
-traceback.install(suppress=[ProcessPoolExecutor])
+# traceback.install(suppress=[ProcessPoolExecutor])
diff --git a/tidy3d/components/data.py b/tidy3d/components/data.py
index 6eddaf3de9..e789c805e9 100644
--- a/tidy3d/components/data.py
+++ b/tidy3d/components/data.py
@@ -658,7 +658,7 @@ def __getitem__(self, monitor_name: str) -> Union[Tidy3dDataArray, xr.Dataset]:
         """
         monitor_data = self.monitor_data.get(monitor_name)
         if not monitor_data:
-            raise DataError(f"monitor {monitor_name} not found")
+            raise DataError(f"monitor '{monitor_name}' not found")
         if isinstance(monitor_data, MonitorData):
             return monitor_data.data
         return monitor_data
diff --git a/tidy3d/components/source.py b/tidy3d/components/source.py
index 5eb1048ab8..e3f138d8f4 100644
--- a/tidy3d/components/source.py
+++ b/tidy3d/components/source.py
@@ -434,9 +434,12 @@ class GaussianBeam(DirectionalSource):
         Specifies the sign of propagation.
         Must be in ``{'+', '-'}``.
         Note: propagation occurs along dimension normal to plane.
-    waist_radius: float
+    waist_radius: float = 1.0
         Radius of the beam at the waist (um).
         Must be positive.
+    waist_distance: float = 0.0
+        Distance (um) from the beam waist along the propagation direction.
+        Must be non-negative.
     angle_theta: float = 0.0
         Angle of propagation of the beam with respect to the normal axis (rad).
     angle_phi: float = 0.0
@@ -457,7 +460,8 @@ class GaussianBeam(DirectionalSource):
     ...     waist_radius=1.0)
     """
 
-    waist_radius: pydantic.PositiveFloat
+    waist_radius: pydantic.PositiveFloat = 1.0
+    waist_distance: pydantic.NonNegativeFloat = 0.0
     angle_theta: float = 0.0
     angle_phi: float = 0.0
     pol_angle: float = 0.0
diff --git a/tidy3d/convert.py b/tidy3d/convert.py
index 848af153ea..571fddb2d6 100644
--- a/tidy3d/convert.py
+++ b/tidy3d/convert.py
@@ -8,7 +8,7 @@
 from tidy3d import Box, Sphere, Cylinder, PolySlab
 from tidy3d import Medium, AnisotropicMedium
 from tidy3d.components.medium import DispersiveMedium, PECMedium
-from tidy3d import VolumeSource, ModeSource, PlaneWave
+from tidy3d import VolumeSource, ModeSource, PlaneWave, GaussianBeam
 from tidy3d import GaussianPulse
 from tidy3d import PML, Absorber, StablePML
 from tidy3d import FieldMonitor, FieldTimeMonitor, FluxMonitor, FluxTimeMonitor
@@ -279,26 +279,28 @@ def old_json_sources(sim: Simulation) -> List[Dict]:
                 "polarization": source.polarization[1],
                 "amplitude": source.source_time.amplitude,
             }
+        elif isinstance(source, GaussianBeam):
+            normal_index = [s == 0 for s in source.size].index(True)
+            injection_axis = source.direction + "xyz"[normal_index]
+            direction = "forward" if source.direction == "+" else "backward"
+            src = {
+                "name": name,
+                "type": "GaussianBeam",
+                "source_time": src_time,
+                "center": list(source.center),
+                "normal": "xyz"[normal_index],
+                "direction": direction,
+                "angle_theta": float(source.angle_theta),
+                "angle_phi": float(source.angle_phi),
+                "waist_radius": float(source.waist_radius),
+                "waist_distance": float(source.waist_distance),
+                "pol_angle": float(source.pol_angle),
+                "amplitude": source.source_time.amplitude
+                }
+
         if src:
             src_list.append(src)
 
-        # """ TODO: Support GaussianBeam """
-        # elif isinstance(source, GaussianBeam):
-        #     src = {
-        #         "name": src_data.name,
-        #         "type": "GaussianBeam",
-        #         "source_time": src_time,
-        #         "position": source.position,
-        #         "normal": source.normal,
-        #         "direction": source.direction,
-        #         "angle_theta": float(source.angle_theta),
-        #         "angle_phi": float(source.angle_phi),
-        #         "waist_radius": float(source.waist_radius),
-        #         "waist_distance": float(source.waist_distance),
-        #         "pol_angle": float(source.pol_angle),
-        #         "amplitude": float(source.amplitude)
-        #         }
-
     return src_list
 
 
diff --git a/tidy3d/web/config.py b/tidy3d/web/config.py
index 0508b569b3..63d961be38 100644
--- a/tidy3d/web/config.py
+++ b/tidy3d/web/config.py
@@ -4,7 +4,7 @@
 from dataclasses import dataclass
 
 # automate this later?
-SOLVER_VERSION = "release-21.4.0"
+SOLVER_VERSION = "release-21.4.2"
 
 
 @dataclass