C++ and blueprints compile but "Failed to load: Can't find file" on building pixelstreaming project.

I’ve been working with the Pixel Streaming plugin for a while now and everthing has worked fine. The project compiles and runs fine on an AWS server, but today I tried to add functionality for some custom input from the external web page and so needed to use the PixelStreaming input component. When I add it to my blueprint everything is seemingly fine, I can hook up all pins just fine and the blueprint compiles. However, when I build the project I get the a whole host of the following errors and warnings:



LogLinker: Warning: Failed to load '/Script/PixelStreaming': Can't find file.
LogLinker: Warning: While loading 'G:/UE4/<ProjectName>/Content/ThirdPersonCPP/Blueprints/ThirdPersonCharacter.uasset' failed to load '/Script/PixelStreaming': Can't find file.

LogBlueprint: Error: [Compiler ThirdPersonCharacter] In use pin PSInputComponent no longer exists on node Set . Please refresh node or break links to remove pin.
LogBlueprint: Error: [Compiler ThirdPersonCharacter] Invalid pin connection from ' ReturnValue ' to ' PSInputComponent '. You may have changed the type after the connections were made.


This is the error I get when I restart the editor:



Failed to load /Script/PixelStreaming.PixelStreamerInputComponent Referenced by ThirdPersonCharacter
Failed to load /Script/PixelStreaming.PixelStreamerInputComponent Referenced by K2Node_CallFunction_3
Failed to load /Script/PixelStreaming.PixelStreamerInputComponent Referenced by K2Node_VariableSet_3

I have tried:

  • Fixing up redirectors (even though I’ve not moved anything around).
  • Refreshing the nodes.
  • Created a new project and tried to reproduce the error, but the new project works fine with the exact same setup in terms of the blueprint.
  • Regenerating visual studio project files.
  • Removing the Intermediate, DerivedDataCache an Saved folders.
  • Disabling and Enabling the plugin.
  • Rebuilding the project.

None of this worked. Does anyone have an idea of where to start digging?

Blueprint:

Hey did you ever figure this out? I’m having a similar issue where my Blueprints compile fine but if I double click any to open in VS it says it can’t find code.

This looks like the same issue that I had (4.25.2), and similar to this: Mod Synth component won't save.

The Synthesis plugin happens to load too late in the engine loading process on startup, which makes it unavailable when loaded after initially being used. Changing the .uplugin file on both plugins to have the "LoadingPhase": "PreDefault" makes these plugins load in before your project files, fixing the issue. .uplugin files are interpreted at load-time, so you don’t need to recompile the engine. The .uplugin file on this plugin is in its folder in (Engine Dir)/Engine/Plugins/Runtime.

Keep in mind that because this change is in engine files, it might not be captured in your source control software. What I plan on doing is making a script that automatically changes out the file for all of my devs’ engine download.

So I’d look at your project .uproject and .Build.cs, and the .uplugin file for PixelStreaming. You somehow need to make PixelStreaming load before your project files, probably with some sort of loading dependency.

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