Hello everyone,
After updating modules, with no apparent error, the only user that could enter the administration web was the one that was logged in at the time of updating.
Detect some problems with the iSymphoni module and uninstall it without any advance.
When you want to enter the administration screen the system makes an attempt to enter, it displays for a few seconds a warning of “unsigned Module (s)” and returns to the start screen.
thank
my best