Hello,
I am trying to merge to Discourse communities together. One is running on an older version so we’re trying to transfer it to a new, and updated forum. I downloaded the old forums back ups and uploaded them to the new forum, but I’m unable to restore the back up file. It says “Restore Failed. Check Logs.”
This is the part that seemed to fail:
What does this mean?
Thanks
Your backup file has been truncated during file transfer, either when downloading or uploading.
Compare the sizes of your original backup, the local copy and the uploaded backup to see where it went wrong.
Then, try again.
We tried again, but it didn’t work
You shouldn’t be restoring another discourse instance in an already active discourse instance. That’s never going to happen that way. There are tools to merge two discourse instances together.
He’s doing it wrong. How can he restore backup from another site to an already existing site? 
Per my understanding he isn’t restoring to a fresh install.
Plus, the ‘old’ discourse should probably be updated before taking backup. Isn’t it?
Yes, you’re right, I totally overlooked the “trying to merge” part. Good that it didn’t work @Infinite_Flight_Sims because you would have lost your new forum!
It is not necessary to update before taking a backup: you can restore a backup of an older discourse version into a newer instance. After restoring, all necessary migrations are run automatically.
The other way around doesn’t work.