If you insert more than 10 user controls in a masterpage, you might get an error similar to this:
The page ‘/path/somefile.master’ allows a limit of 11 direct dependencies, and that limit has been exceeded.
You can easily increase that limit as it is actually set in your sharepoint web.config:
1) Browse to C:\inetpub\wwwroot\wss\VirtualDirectories\
2) Open the folder corresponding to your Sharepoint website.
3) Edit the file web.config
4) Do a search for “safemode“.
5) Change the property DirectFileDependencies from 10 to a value your choice.
6) Do an iisreset command and you’re done!