Engine Freezes Compiling Fmod Material

When Saving the Material shown below, the engine will freeze at 50%, no crash is generated but engine stays unresponsive (tested for 60 mins) and must be terminated via Windows Task Manager.

[Image Removed]

The odd behavior is that if the B input to the Fmod node is a Scalar Parameter instead of a Constant 1, freezing does not occur.

This is a regression from behavior in 4.7.6.

Also tested and reproduced in Main Promotable-CL-2599540

1. Open QAGame Editor
2. Create a New Material
   ==Recreating Material pictured in Description==
3. Take PIxel Depth and Multiply it by a Gradient Texture (Texture2D'/Engine/EngineResources/GradientTexture0.GradientTexture0')
4. Add a Fmod node
5. Plug the results of the Multiply into Fmod input A
6. Add a Scalar Parameter of 1.15
7. Plug the Scalar Parameter into the Fmod input B
8. Plug the Fmod Output into Emissive Color (any Material input will cause issue)
9. Save Material
10. Convert Scalar Parameter into a Constant 1
11. Save Material

RESULTS: Engine Effectively Freezes

EXPECTED: Same Shader Compile Times as with Scalar Parameter

Changing input of Fmod material node crashes while saving