In order to get the File system verify or repair failed. : (-69845) error message fixed, you'd better make sure you have a backup of the data stored in the external hard drive so that you can perform some professional methods. For instance, run First Aid in Disk Utility again, reformat this drive in Disk Utility, and so on.
Before switching to professional methods, you can give the device reboot a try. Just restart your Mac and check if the trouble is still there. You can also insert the problematic external hard drive into another computer to see if the same trouble hits as long as you get one.
On top of that, you can also repair it again in Disk Utility or reformat the drive to rule out the error information. iBoysoft Data Recovery Software is available for you to grab your data if you have no backup.
With data at hand, now you can fix file system verify or repair failed: (-69845) with ease.
Solution 1: How to repair the external hard drive in Disk Utility:
1. Use Finder, go to Applications then Utilities, and select Disk Utility.
2. From the drives listed on the sidebar, select the hard drive that you are going to work on it.
3. Finally, click on First Aid at the top of the Disk Utility window. Then the app will start, and it may take a while for the repair process to finish.
Solution 2: Reformat the drive in Disk Utility
When you are ready, follow the steps below to format the drive and fix "File system verify or repair failed. : (-69845)" on Mac.
Step 1: Go to Disk Utility.
Step 2: Click the drive that's facing error 69845 from the left sidebar.
Step 3: Click Erase on the top of the window.
Step 4: Provide a Name and Format, then click Erase. It will take a while to finish the erasure process.
Step 5: Click Done when it ends.
Hope this answer helps!
