EP Issue: The User Control *name.ascx* has caused a compilation error.

Continuing with EP deployment issues seen during an implementation and deployment to higher environments; an issue can occur where an error occurs within Enterprise Portal on various commands and processes that says:

'The User Control *name.ascx* has caused a compilation error. To view the details about this error, enable debugging in the web.config file or view the Windows event logs.'

This issue is caused by a similar problem we covered in a previous post (EP Issue: Web Control is not deployed)

An example where this can be encountered is on creation of a new Expense Report line. This boils down to missing files in one of the EP folders on the Enterprise Portal web server. These files are located at 'C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\Template\Layouts\ep'.

Solution:

1. Copy the files from a working EP environment from the folder and paste them into the environment folder that is not working. Obviously take backups of everything before doing any of this. 
2. Run IISRESET on EP server