This address in your project states that the material issue in question is part of the Engine (line 4521 of the .cpp file "HLSLMaterialTranslator). Either the material itself is broken (which means too bad use something else if you got it from Megascans) or the .cpp file is corrupted, which an engine verify should theoretically fix. The problem can literally only be:
- The material
- The .cpp file HLSL Material Translator
- Their communication lines
You could try deleting and redownloading it from Quixel as well. Regardless, it’s corruption, so the only way to fix it is to refresh and hopefully get an uncorrupted file. 