# Blank screen after selecting a workflow **URL:** \ **Category:** 🤝 Community Help\ **Tags:** bugs\ **Created:** [March 3, 2025, 6:25pm UTC](https://discuss.roboflow.com/t/blank-screen-after-selecting-a-workflow/8876 "2025-03-03T18:25:43Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![LouNL](https://avatars.discourse-cdn.com/v4/letter/l/cab0a1/32.png) [@LouNL](https://discuss.roboflow.com/u/LouNL)\ **Post date:** [March 3, 2025, 6:25pm UTC](https://discuss.roboflow.com/t/blank-screen-after-selecting-a-workflow/8876/1 "2025-03-03T18:25:43Z")
When I click on any workflow on the workflow editor it gives me a blank screen: ![image](https://canada1.discourse-cdn.com/flex029/uploads/roboflow1/original/2X/f/fd6f106139a484b1ee30224aaa102c8fc0cec183.png) This was all working fine earlier. The only difference today is I connected a local server and tried adding a custom Python block, which apparently didn’t work (see output below). That crashed the local server. I restarted it, deleted all workflows, and tried to add one again. Still blank. > C:\Windows\System32\>docker run -p 9001:9001 --name roboflow roboflow/roboflow-inference-server-cpu:latest > UserWarning: Field name “schema” in “WorkflowsBlocksSchemaDescription” shadows an attribute in parent “BaseModel” > WARNING:tzlocal:/etc/timezone is deprecated on Debian, and no longer reliable. Ignoring. > INFO: Started server process [7] > INFO: Waiting for application startup. > INFO: Application startup complete. > INFO: Uvicorn running on [http://0.0.0.0:9001](http://0.0.0.0:9001) (Press CTRL+C to quit) > INFO: 192.168.65.1:38453 - “OPTIONS /workflows/definition/schema?api\_key=cKfxce4zMzd9AD5yMq3D HTTP/1.1” 200 OK > INFO: 192.168.65.1:16954 - “OPTIONS /workflows/blocks/describe?api\_key=cKfxce4zMzd9AD5yMq3D HTTP/1.1” 200 OK > INFO: 192.168.65.1:16954 - “GET /workflows/definition/schema?api\_key=cKfxce4zMzd9AD5yMq3D HTTP/1.1” 200 OK > INFO: 192.168.65.1:38453 - “POST /workflows/blocks/describe?api\_key=cKfxce4zMzd9AD5yMq3D HTTP/1.1” 200 OK > INFO: 192.168.65.1:34712 - “OPTIONS /workflows/blocks/describe HTTP/1.1” 200 OK > INFO: 192.168.65.1:34712 - “POST /workflows/blocks/describe HTTP/1.1” 200 OK > INFO: 192.168.65.1:49245 - “OPTIONS / HTTP/1.1” 200 OK > INFO: 192.168.65.1:49245 - “HEAD / HTTP/1.1” 200 OK > INFO: 192.168.65.1:49245 - “OPTIONS /workflows/definition/schema HTTP/1.1” 200 OK > INFO: 192.168.65.1:24357 - “POST /workflows/blocks/describe HTTP/1.1” 200 OK > INFO: 192.168.65.1:49245 - “GET /workflows/definition/schema HTTP/1.1” 200 OK > INFO: 192.168.65.1:41298 - “HEAD / HTTP/1.1” 200 OK > INFO: 192.168.65.1:41298 - “OPTIONS /workflows/run HTTP/1.1” 200 OK > UserWarning: Specified provider ‘CUDAExecutionProvider’ is not in available provider names.Available providers: ‘OpenVINOExecutionProvider, CPUExecutionProvider’ > UserWarning: Specified provider ‘CoreMLExecutionProvider’ is not in available provider names.Available providers: ‘OpenVINOExecutionProvider, CPUExecutionProvider’ > Traceback (most recent call last): > File “/app/inference/core/interfaces/http/http\_api.py”, line 267, in wrapped\_route > return await route(\*args, \*\*kwargs) > File “/app/inference/core/interfaces/http/http\_api.py”, line 1263, in infer\_from\_workflow > return process\_workflow\_inference\_request( > File “/app/inference/core/interfaces/http/http\_api.py”, line 760, in process\_workflow\_inference\_request > workflow\_results = execution\_engine.run( > File “/app/inference/core/workflows/execution\_engine/core.py”, line 73, in run > return self.\_engine.run( > File “/app/inference/core/workflows/execution\_engine/v1/core.py”, line 107, in run > result = run\_workflow( > File “/app/inference/usage\_tracking/collector.py”, line 664, in sync\_wrapper > res = func(\*args, \*\*kwargs) > File “/app/inference/core/workflows/execution\_engine/profiling/core.py”, line 264, in wrapper > return func(\*args, \*\*kwargs) > File “/app/inference/core/workflows/execution\_engine/v1/executor/core.py”, line 62, in run\_workflow > execute\_steps( > File “/app/inference/core/workflows/execution\_engine/profiling/core.py”, line 264, in wrapper > return func(\*args, \*\*kwargs) > File “/app/inference/core/workflows/execution\_engine/v1/executor/core.py”, line 108, in execute\_steps > \_ = run\_steps\_in\_parallel( > File “/app/inference/core/workflows/execution\_engine/v1/executor/utils.py”, line 14, in run\_steps\_in\_parallel > return list(inner\_executor.map(\_run, steps)) > File “/usr/local/lib/python3.9/concurrent/futures/\_base.py”, line 609, in result\_iterator > yield fs.pop().result() > File “/usr/local/lib/python3.9/concurrent/futures/\_base.py”, line 439, in result > return self.\_\_get\_result() > File “/usr/local/lib/python3.9/concurrent/futures/\_base.py”, line 391, in \_\_get\_result > raise self.\_exception > File “/usr/local/lib/python3.9/concurrent/futures/thread.py”, line 58, in run > result = self.fn(\*self.args, \*\*self.kwargs) > File “/app/inference/core/workflows/execution\_engine/v1/executor/utils.py”, line 37, in \_run > return fun() > File “/app/inference/core/workflows/execution\_engine/profiling/core.py”, line 264, in wrapper > return func(\*args, \*\*kwargs) > File “/app/inference/core/workflows/execution\_engine/v1/executor/core.py”, line 140, in safe\_execute\_step > raise error > File “/app/inference/core/workflows/execution\_engine/v1/executor/core.py”, line 130, in safe\_execute\_step > run\_step( > File “/app/inference/core/workflows/execution\_engine/v1/executor/core.py”, line 160, in run\_step > return run\_simd\_step( > File “/app/inference/core/workflows/execution\_engine/v1/executor/core.py”, line 190, in run\_simd\_step > return run\_simd\_step\_in\_non\_batch\_mode( > File “/app/inference/core/workflows/execution\_engine/v1/executor/core.py”, line 269, in run\_simd\_step\_in\_non\_batch\_mode > execution\_data\_manager.register\_simd\_step\_output( > File “/app/inference/core/workflows/execution\_engine/v1/executor/execution\_data\_manager/manager.py”, line 251, in register\_simd\_step\_output > self.\_execution\_cache.register\_batch\_of\_step\_outputs( > File “/app/inference/core/workflows/execution\_engine/v1/executor/execution\_data\_manager/execution\_cache.py”, line 100, in register\_batch\_of\_step\_outputs > self.\_cache\_content[step\_name].register\_outputs( > File “/app/inference/core/workflows/execution\_engine/v1/executor/execution\_data\_manager/execution\_cache.py”, line 320, in register\_outputs > raise ExecutionEngineRuntimeError( > inference.core.workflows.errors.ExecutionEngineRuntimeError: Step count\_overlaps did not produce required outputs. Expected: {‘overlaps’}. Got: set(). Contact Roboflow team through github issues ([GitHub · Where software is built](https://github.com/roboflow/inference/issues)) providing full context ofthe problem - including workflow definition you use. > INFO: 192.168.65.1:41298 - “POST /workflows/run HTTP/1.1” 500 Internal Server Error ---
**Author:** ![LouNL](https://avatars.discourse-cdn.com/v4/letter/l/cab0a1/32.png) [@LouNL](https://discuss.roboflow.com/u/LouNL)\ **Post date:** [March 3, 2025, 6:51pm UTC](https://discuss.roboflow.com/t/blank-screen-after-selecting-a-workflow/8876/2 "2025-03-03T18:51:27Z")
I was able to workaround this by clearing my browser cache (specifically “cookies and other site data”), but I don’t think that should be considered a solution. ---
**Author:** ![Grzegorz](https://yyz1.discourse-cdn.com/flex029/user_avatar/discuss.roboflow.com/grzegorz/32/2877_2.png) [@Grzegorz](https://discuss.roboflow.com/u/Grzegorz)\ **Post date:** [March 4, 2025, 10:05am UTC](https://discuss.roboflow.com/t/blank-screen-after-selecting-a-workflow/8876/3 "2025-03-04T10:05:18Z")
Hi @LouNL , Thank you for reporting this bug. Indeed, when custom python block does not provide outputs as outlined in block configuration, the UI will encounter unhandled exception. We are working to fix this issue. However, to fix the state of UI it should be enough to refresh the app (I did not have to clear cookies and site data in order to fix the app state). Thanks once again, Grzegorz ---
**Author:** ![LouNL](https://avatars.discourse-cdn.com/v4/letter/l/cab0a1/32.png) [@LouNL](https://discuss.roboflow.com/u/LouNL)\ **Post date:** [March 6, 2025, 8:41pm UTC](https://discuss.roboflow.com/t/blank-screen-after-selecting-a-workflow/8876/4 "2025-03-06T20:41:14Z")
Ok, good to hear it’ll be fixed. I only seem to be able to recover when clearing the site data. It’s easily reproduceable for me if there’s any info you need (ex. console logs or something) ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex029/uploads/roboflow1/original/1X/bb6edbfa56d0cf2ee603f061e9e09103502cc8cc.png) [@system](https://discuss.roboflow.com/u/system)\ **Post date:** [March 27, 2025, 8:42pm UTC](https://discuss.roboflow.com/t/blank-screen-after-selecting-a-workflow/8876/5 "2025-03-27T20:42:04Z")
This topic was automatically closed 21 days after the last reply. New replies are no longer allowed.