So I recently had to format this handed-down 13" late 2011 MacBook Pro due to some system instability I had due to too many RAM changes, and when I was setting up the OS I, again, turned on FileVault. I used my computer as normal, probably too much as normal, installing a bunch of things, moving files, rebooting, force shutting down when the computer froze for too long, and after a while I realised the computer was getting really laggy and encryption wasn't advancing at all, with FileVault saying "Estimating time remaining" and, at times, "More than one day remaining", which quickly changed back to "estimating" again. For several hours it was stuck at what I learned with diskutil was 57%. I looked around for solutions, and even though people's problems were that encryption was at "Connect power adapter to resume encryption" even though they did have it connected, I tried out every solution I could find (First Aid, SMC, NVRAM, a few commands, etc.). In the end, I found a command to revert encryption, I tried it in the recovery disk, rebooted, and was glad to find it says "decrypting" along with a real time estimate and the progress bar was now at 42%. Thing is, it never moved from 42%. I formatted, reinstalled, didn't set up FileVault until I could leave the computer by itself as to avoid the same problem again. I set it up and went to sleep. A few hours ago I woke up and guess what: 57% again. Is there any solution or do I have to format for a third time and just don't ever use FileVault?