That is why you actually need to read the howtos and errata files before you do something which might affect i-MSCP.
There are ways how to downgrade again, which might need a bit of work.
So far, I think the issue isnt directly the phpswitcher module. Its more like an issue raised by the upgrade.
Did you tried to uninstall and remove that plugin and after that re-install it?
Either you downgrade or try to fix the issue which you got now. Or you do wait till Nuxwin or other projects-members are seeing this topic.^^