This is an awful practice. It eliminates context and previous lessons learned. It also keeps those who have awareness of the issues being informed when something new related to it is posted since they are not following the new threads already.
I totally agree that closing out threads that get off track is an occasional ok practice when it doesn't lock out awareness of valuable trouble shooting.
By closing these threads, folks who've had their problem solved can't post in the existing threads so it looks like the problem was never solved...as in this case.
I did post links to the previous threads, but I was already so irritated by them being closed and preventing awareness of this issue already being solved, that it basically turned into a rant from me.
Also, I didn't upgrade to a weird version. I updated to the version every said I should 3 years ago and haven't gotten a prompt in the UI since to upgrade that version to something newer. Prior to 5.0.14, I'd occasionally get prompted to update the firmware which I would do. Did upgrading to 5.0.14 eliminate that because I was on some funky version?