File History has stopped functioning

So, I was never able to fix this. But I did exclude two folders in which error messages were always occurring. And it ran once I excluded the folders.

BUT.... I tried it today, and now there is a completely different problem. it is not launching the backup. When I plug it in the PC recognizes that drive is plugged in, and the "run now" link appears, but clicking on it does nothing......

Takket​ 

Based on your description in the image above, my problem is different from yours. The error occurred on June 1, 2026, at which point the archive history could be accessed.

Mine is showing the same symptoms. The last file date I see on the external drive in the archive history is July 28, 2026, and KB5101684 was updated on July 29, so it's clearly related to KB5101684. It's still staging files on the C drive, and I've wasted too much time trying to fix this. I hope the next cumulative update will fix it; it's excessive that Microsoft refuses to admit its mistakes.

File History has recently stopped working for me.  I have tried numerous fixes, including those mentioned by several of the other contributors.  Nothing worked.  This is very frustrating.  

Same symptoms.  The last files I see on my external drive under File History are from 7/14/26, so it's pretty obvious that it's related to KB5101650 or KB5100998.  It is still staging files on C:, and I've wasted enough time trying to fix this.  I'm hoping the next cumulative addresses it.

File History Fixed!

Backup Hard Drive:  WD My Passport Ultra (3 TB, USB)

So I've had this problem recently, I don't know when it actually started because I haven't used it lately, but the symptoms are the same as the above posts.  File History seemed to work but no files saved in the Data folder.   I've spent 2 days trying every fix I can find and I finally got it to work by uninstalling Microsoft KB101650 Security Update.  I guess I could try re-installing it, but I hate to take a chance on it.   Good Luck to All!

Update:  After opening Windows Update these 2 Security updates were there to be installed:

KB101650 and KB100998

I saw no way to opt-out of either of these as Windows Update said they would be installed in the next restart, so I went ahead with the restart and installed them.   File History did work OK after the install.  So, was there something wrong with KB101650 or was it just a bad install?  I'm sure I'll never know.

I'm having the same problem.  File History is not saving the files.

I've also been experiencing issues with File History refusing to turn on and run. It had been automatically running fine for almost a year, and then failed with some vague error message and asked me to designate the drive on which to store the data. It had been saving to the same 128Gb mini-SD in an adapter (formatted as exFAT, not NTFS) that always stayed in the designated slot on my laptop without ever being removed by me. As it was my designated device for keeping my File History updated, I had no reason to remove it. 

When I opened File History from the Control Panel, it still showed the same SD card with the same drive letter it had always been. So I selected to Run Now, and the whole error process started again. 

As the 128Gb SD card only had 24Gb of free space remaining, I thought maybe there wasn't enough space. So I purchased a new SanDisk Ultra 512Gb SD card with plans to start all over again. Problem is, it wouldn't let me select the new drive and presented me with another vague reason that it couldn't use a different target drive than the one already designated. I did quite a bit of research and ended up deleting all the former configuration files that were resident on my SSD C: drive as directed by the solutions presented in my research. I turned off File History, and was then able to select the new SD card upon which to save all my File History. When I left-clicked on <Turn On> in the File History window, it would gray out for a number of seconds as if it was going to begin saving files, but then would fail to start.

Did more research and it said to open services.msc from the Start>Run entry box and check to see if File History was actually running. I did, and it wasn't. So I started the File History service, which was set to "Manual" as the trigger to start the service. I then set it to start automatically going forward (NOT Automatic - Delayed Start), which is what my research said to do. 

After restarting my laptop, I went back into Control Panel>File History and it was showing that the service was turned off, despite my going into services.msc and manually starting it. So I went back into services.msc and, sure enough, it wasn't running and had reverted back to a Manual start, even though I'd changed it to Automatic. I switched it back to Automatic and started the service again. Then I reopened Control Panel>File History and it was again turned off. I left-clicked on <Turn On> AGAIN, and it repeated what it did before - graying out and looking like it was going to work - but it never did. So, I'm currently in this endless loop of File History failure and don't know what to do to fix it.

FYI...

I've run DISM Restore Health and sfc /scannow and all is well - no corruption found. I've also been going back in to the C: drive Windows/File History/Configuration folder and deleting all the files in there (as directed to do in my research findings) that the process creates each time I click on the <Turn On> button in Control Panel>File History. Then I restart my laptop again and repeat the process stated in the paragraph directly above the "FYI...", etc., etc., etc.

Based on my research, the issues you're experiencing likely stem from the drive not being properly detected by Windows services or corruption in the system components that File History relies on.

Ran DISM and SFC. DISM ran for quite a while and repaired some things, but it didn't tell me what. File History still doesn't work. Same problem. Though the error message has changed:

Unusual condition was encountered during finalization of a backup cycle for configuration C:\Users\jctak\AppData\Local\Microsoft\Windows\FileHistory\Configuration\Config

I was able to run a full system image which ran without any errors at all. 

Update: Ran chkdsk which corrected many "reparse" points (which is an error i had seen a few times on File History). After doing that i deleted the config/data files to start file history fresh and ran it again. it ran for over 30 minutes so i was thinking it was actually copying files but then... nope. it ended, threw the same error, and a check of the backup drive showed no files had been copied. so... i don't know what it thought it was doing for 30 minutes? but it did nothing.