I have a huge problem with Magento on a live platform.
I've disabled a few modules, which I don't use, via a command line. I've made it before already and had no problems with it. 
But now I can't upgrade or deploy.
I get this error:

Invalid argument supplied for foreach() in /vendor/magento/module-store/Model/Config/Processor/Fallback.php on line 125

I've enabled the modules again, but the error stays.

What could I do?
Appreciate any help.