Unkown compilation error VS C++

Hey everyone I am not sure why but I am getting this error in my project that I never got before: Could not find extern declaration for cross module reference Z_Construct_UScriptStruct_FGameplayTag()

I am using UE4.8 with nvidia tech and about a few weeks ago it was compiling fine, I tried extending AIController and that compiled fine, then I tried adding data tables and then that error is plaguing my project. The log is not helpful at all, I either get that error or other compilation errors(5). as the error… Visual studio integration has been very poor with handling errors and logs and not really telling me what is wrong at all so it is a bit of a pain to debug.

I thank you for taking the time to read this post and I look forward to any and all help as I have googled that error and got zero results so it is a bit disheartening.

Try rebuilding the code. What may also help is to include whitelines into the header and cpp files in the first line: It may sound outlandish, the VS contencunates the code and including whiteline may make a difference.

Let me know if it works.

yeah that was part of it, also moved some functions into a Blueprint Library Function.h class and that cleared up the other issues. Not really sure why though as it wasn’t giving any errors with having the function in a seperate .h/.cpp files. The weird thing is it did that even when they had no code (minus what is generated when making a new class)