Hello,
I was asking about css/JS because these resourced are most likely to get cached and sometimes they require clearing browser cache.
But I believe I know where the issue lies now - the mobile version keeps the details regarding currently displayed error in session. If you enter a screen that triggers error based on the variables set in session, it is possible you may be locked in this state until you log out/clear cache.
There is another solution for this situation and it's to append back parameter to url, with value set to 1:
http://localhost/epesi/mobile.php?back=1
Of course you need to change the localhost/epesi/ to your EPESI address.
This should bring you to the main menu for mobile version and it should clear all the values that cause the error.
Hope this helps,
Arek