Check version of all dlls. Epi cant find the one for applicationmodules with correct version.
Check bin folder if its there. Make sure the reference in your project goes to correct version. Set copy local if needed in VS. Also check the assemblyredirects in web.config and make sure those are correct. Compare vs example site if needed
New deployment of the code I've been developing worked fine the first day after deployment. I came in this morning to the following error