Don’t want to open a new Thread, but I have the same problem, but I am currently on 11.0.3 and I am unable to upgrade to 12.0.0. I did the same procedure as always, that means, deleting everything in the nextcloud folder apart from the config folder and copy the config.php into the new installation and do edit the .htaccess with some minor modifications.
When clicking the update button it quits working with the above error message that Updates between multiple major versions and downgrades are unsupported. It’s a bit strange because I am already on the latest stable version of the predecessor.
Any hints?
Discussed at length on the forums - output the version number listed in your config.php file please.
Hi Jason!
Hm, I did search in the Forums, but did not exactly foud what I was looking for 
I modified the config.php with the new version number (in my case: ‘version’ => ‘12.0.0.29’,) but that did not solve my problem. The other fields I left unmodified as I also did in the past without any troubles.
Can it also be a server right issue? On one webspace running php5 I had to set the rights, the “troublemaking” one is on php7 via cgi and all the rights are by the user. On nextcloud 11 without any issues.
You need to edit it to show the previous version, say 11.0.3 for example. 
Maybe I am blind, maybe stupid. I always edit the version parameter in the copnfig.php according to the version.php in the mainfolder.
If I now put an older version into the config.php the error persists… I am really confused…
Right, so if you’re on 11.0.3 now and looking to upgrade, you’d have 11.0.3 as the version number in the config.
This error usually shows up when the version number you’re migrating from is miles off what it should be.
If it isn’t that, perhaps someone else will have an idea.
Thank you Jason. Just to confirm, I do a manual update, means, I upload the new nextcloud folder (12.0.0.29) into the root directory. Then I copy the old config.php in the config-folder and edit the version parameter accordingly. That’s how I always get a running Nextcloud installation only the new version does not run smoothly.
As stated above, with the server running php5x I did not have any issues. Only the one with php7 (via cgi) won’t update as expected.
Maybe that’s the culprit but I am not really willing to downgrade the php version especially beause the 11.0.3 ran without an issue.
I am still confused 
Can’t comment on CGI as I don’t use it, but nor have I ever manually edited the config to update the version number, Nextcloud usually does that for me.
Backup your data, config and optionally apps/themes, setup a fresh environment, push your backed up data back into the NC dir and try an occ upgrade. Perhaps that’ll get it up and running. I’d return your version number to 11.0.3.2 also.
Thanks for that hint. Well, I did also some research here on the forum and it seems that others have the same difficulties with getting the update done on php7 (or a similar setup).
Well, I did modify the updater.php in lib/private as described Here. That did the job perfectly.
Hmm, glad it worked but that’s a bit of a risky approach.
Hopefully the next upgrade (12.0.1) and further go smoothly for you now though.
I am not entirely sure why that workaround should be “risky” as I have reedited the file after the successful installation. I just wonder whether it persists with the next minor upgrade or not. Fingers crossed.
Because you’re telling the updater to go ahead regardless of version checks. Fine in your particular scenario perhaps though someone seeing your workaround in the future trying to come from NC10 to NC17 (or something) will possibly obliterate their install by skipping major intermediate updates. That’s all it is.