http://developers.de/blogs/damir_dobric/archive/2015/07/28/filenotfoundexception-in-getsignature.aspxWhen working with Workflow Manager, you might run into some none deterministic compiler errors. One of these errors sounds like: FileNotFoundException Could not load file or assembly… at GetSignature() This is the screenshot of the error generated inenCommunityServer 2008 SP1 (Build: 30619.63)