Epicor reports compile errors although code is correct
When code modifications are made to existing well compiled code, the customization wizard doesn't always save the new customization correctly and therefore reports compile errors.
This can be verified by opening the temporary .cs file created by Epicor to perform the compile. The directory is C:\Documents and Settings\All Users\Application Data\Epicor\epicor-9421\9.05.605\aa\CustomDLLs.
Run the application until the Application Error is displayed, then open the directory and sort by modified date. Open the .cs file and verify the code matches the what's expected.
To resolve issue, re-enter all code modifications for the form starting with the base form. Do not edit existing code, create code from scratch.