Hi devil495,
All plugin code lives in the respective wp-content/plugins/(plugin-name) directory/. If you rename or delete the directory of an active plugin, then:
a) the front-end will break, because the front-end insists that active plugins exist
b) the back-end will not attempt to load the moved/deleted plugin, but will instead de-activate it
Thus, if a site breaks, and if you suspect it's a plugin, then you can safely move/delete all of them in turn, until you find the culprit. If moving updraftplus hasn't regained you the ability to login on the back end (i.e. via /wp-admin), then UpdraftPlus wasn't the culprit.
So, yes, rename them all in turn, using a process of elimination to find the offender.
David