To solve a problem I disabled my Wordpress CloudFlare SSL plugin which took my site down… not good, after several hours of reading, testing, contacting my host (GoDaddy), I found this very similar article:
which does not have a happy resolution… then I figured out how to reactivate the CloudFlare plugin without much effort. There are a number of steps involved, but the key is to copy the CloudFlare SSL plugin files into a MU-PLUGIN folder that you create.
I documented the process and included screen shots here: https://www.urtech.ca/2019/06/solved-easily-reactivate-deactivated-plugins-in-wordpress/ if you need more details.
I hope this helps.