I am moving to a new computer, so this problem may in some way be related to the way I have my files set up. After successfully upgrading to the newest ANKI version, I was able to backup at least once. I have, over the last day, attempted to do a full collection backup with media, and every time the process gets stuck at 4218 media files and continues to act as if it was still working on backing up. I have left the computer for ten or fifteen minutes to come back to the same. This morning I had the same problem. In addition, something happened that makes me think that I may have some setting wrong in my computer. It warned, “do you want to replace file of the same name” or something like it. If I remember correctly, in the past it included more information such as the time of the day, as part of the file name, and so one might back up more than one time and just generate a new backup. I’m not sure about that. Also, when I look at the folder, the backup file, even though it seems as if it did not complete the process, seems to be there. Any help would be most appreciated. Thanks again.
When you use File>Export and export a .colpkg file, the resulting file should be called something like collection-2021-06-03@11-12-02.colpkg. It shouldn’t be getting stuck though, that’s odd. No error messages pop up? If you use Tools>Check Media prior to exporting, does that help?
You replied on the other site, but it would be easier to follow up here. Since Check Media did not help, please open the Windows Task Manager before you start exporting, and keep an eye on the CPU and memory usage. How does it change as the export proceeds? What is it doing when it reaches the point you get stuck?
CPU between 11 and 13%, Memory usage at 206.3 MB (stable), Disk is 630 MB/second with a little variation.
Any ideas on how to solve the backup problem? Or how to test if the backup that is being created will work? Can I install ANKI on two PCs meanwhile? If so, how would I do that?
That is odd. Which folder are you exporting into? Does it make a difference if you export to a different location?
I also recommend looking inside your media folder. Do you have any very large files in there? Managing Files - Anki Manual
I reduced the size of a large photo (there was only one) and attempted a different file location. This did not solve my problem. Any help would be most appreciated. Thanks!
Hmm. Please go to the Performance tab, click on Open Resource Monitor, then go to the Disk tab and expand the disk activity section. What file(s) is Anki reading or writing so much?
Hi Damien. Where is the performance tab? How do I find it? I assume that is in the PC? Thanks.
So, I tried something. I attempted to download ANKI onto my former computer. It asked me if I want to download from ANKI Web. I said yes. It downloads only 60% and gets stuck there. I finally had to stop the procedure. Does this give us any hints at all as to what may be happening?
Could be a temporary network problem, could be something strange with your computer. Maybe a restart might help?
I have done all of these things and checked different folder and everything else. Is there anyway I can revert to an older version of ANKI? The reason I ask is because I have spent months of time into my ANKI collection and need to back it up on a regular basis. Any help would be so appreciated.
Yes, older versions are linked from the Anki website. You’ll need to downgrade first. Please let us know if that actually resolves the issue for you.
Thanks, I will keep you informed.
Error message when I tried to downgrade and then install and then open: “The following profiles could not be downgraded: User 1.”
I never had a problem with backup until this new version. 
That message implies you tried to downgrade with an older version. The downgrade+quit button must be used on the latest Anki version, before you switch to an older version.
Then Version 2.1.44 (b2b3275f) is not the latest?
I had a thought. Is there a way to backup each one of my different decks separately, including the media, and in that way determine in which of my decks the error exists? Also, the APKG backs up without a problem. The only problem I have is when I try and backup the collection COLPKG? What is the difference between these two? Thanks for the help. I study my ANKI two hours a day or more and it is an integral part of my life. I have spent months creating these decks and just do not want to lose them. I would really appreciate some help.