I've been running my server for a year now and recently the pen drive has been showing as being almost completely full, it's 8GB. I'm on v6.3.5 and when I plug the pendrive into another PC it shows only about 500mb being used. The system has crashed at least once that I know of because of this and today I did a reboot and now it won't load. The system posts normally but when unraid tries to load I get a message on the screen that simply says "Boot Error" 

Put it in your PC and let it checkdisk.

I ran a check disk on a windows pc then tried to boot it again but same boot error

Might be time to get a new pen drive and transfer your license to it.  Obviously make sure you can boot unRAID and test everything out with a trial license first before transferring your existing license over.

I reformatted the pen drive, reinstalled unraid, reinstalled dockers/plugins without any issues and things seem fine. 

Only problem with that approach is I don't think we ever really got to the bottom of the problem in the first place.

 

I guess you could see how it goes, but I'd echo @BobPhoenix's suggestion of replacing the drive at the merest hint of trouble.

Well you guys were right it broke again. I started setting up a new flash drive, I wanted to copy the old drive to reduce the setup time as much as possible but then when I tried to copy things some folders wouldn't copy. I dug into it and well you can see in the attached images it's pretty weird. These are the only 2 plugins like this, everything else looks normal and I can't open any of these folders. 

Edited September 19, 20178 yr by Zodis

If it were me I would set everything up from scratch again.  The only thing I would copy to the new flash drive is the "super.dat" file.  But someone else may suggest a better option for you.  I can usually setup unRAID the way I want in an hour or less with all plugins and my ONE docker.