There's been a whole bunch of posts with the same kind of error description posted here over the years.
This appears to be some kind of data file damage that Quicken is unable to detect and repair.
In a nutshell, you need to either find the damaged transaction record and delete, then reenter itor restore your data file from a backup taken prior to the time you first detected this problem.
https://www.quicken.com/support/how-backup-or-restore-your-quicken-data