Presistent Object Inconsistency error

I've recently started getting the error message: "Presistent object inconsistency" Error in file: C:/BuildAgent/work/14194e8ce88cdf47/Runtime/Misc/SaveAndLoadHelper.cpp at line:1182

Im not sure what's causing it and it spams about 1000 lines of this error instantly. It happens when I stop the play button on Unity's Editor. Any suggestion on what could be causing this and a fix? Much appreciated.

I have two AssetBundles that load via IEnumerator function from the internet. Not sure if that's related.

Unity Pro 3.5.7f6

Please let me know if you need any more information!