What version of Oxwall are you running and what version of php do you have, check your php using ONLY phpinfo()
does not allow php version
in plug-ins do not have php validation???
It hung in the maintenance mode, the system
the upgrade is not checking php, there may be problems
https://developers.oxwall.com/forum/topic/24133
i personally deactivate all plugins not just third party plugins.
It is necessary to put a new version of debian
the easiest way, hosting panel with the problem, it's easier to reinstall all
otherwise it is a dance with a tambourine
which version works on 5.4
take another hard disk will reinstall the system