Issue with register periodically subtracting $800, Using Quicken Classic Deluxe R66.28 [Edited]

By any chance are you, periodically, changing the value of the OTHER-SIDE of a transfer to/from this account?

Or, deleting a to/from transfer?

A transfer, in Q, is a two-sided transaction and changing one-side changes the other side also.

And, is it always exactly $800? Which is what made suspect a change to a transfer.

Also, what type of account is this happening in?

Does this issue occur after you reauthorize the account, do Reset Account or deactivate/reactivate the account? If so, there is a long-standing known issue where the amount of the Opening Balance transaction will sometimes get changed when anything is done that causes a change to or refresh of the account's download connection.

Even if you are not sure, you might want to restore an old backup file (preferably dated from before this issue started occurring) and make note of what the amount of the Opening Balance transaction is. Then compare that to what is shown in the current data file. If they are not the same that it is likely that this is at least contributing to the issue you are posting about. Back up your data file and then correct the amount shown for the Opening Balance transaction in your current file.

Doing this might not resolve the account balance issue if you have been making account balancing transactions along the way to adjust for this issue. If that is the case, you will need to delete those account balancing transactions, too.

"Reauthorize" is when Quicken informs you that the financial institution needs you to reauthorize the account for downloading. During this process Quicken will open a financial institution webpage in your Internet browser where you will need to log in and then authorize the financial institution to provide your financial data to Intuit and/or Quicken. When completed you will (or should be) taken back to the Quicken app.

"Reset Account" is a button on the Online Services tab of Account Details. When there is a persistent issue with downloading, sometimes the download connection needs to be reset to start working properly, again.

"Deactivate" is also a button on the Online Services tab of Account Details. It causes a hard and complete break in the download connection. It is sometimes needed when Reset Account does not fix the connection or when you want to change the type of connection the account is set up with (example, change the connection from Direct Connect to Express Web Connect+). "Reactivate" simply means to set up a new connection via Add Account or Set Up Now after an account has been Deactivated.

(At the tail end of each of these processes, Quicken will attempt to link the new or updated connections to the accounts that are already in Quicken. You might be prompted to assist in this and when that happens make sure you LINK the downloaded data to those existing accounts in Quicken.)

Any one of these processes can sometimes cause the Opening Balance transaction dollar amount to be changed. They can also sometimes cause there to be some duplicate transactions entered into account register (that typically would occur sometime within the last 90 days). More often than not, these issues do not occur but to be on the safe side it is recommended to enter the correct Opening Balance transaction dollar amount into the Memo field of that transaction. That makes it very easy in the future to determine if the dollar amount was changed and how to fix it.

I don't think there was an update in the past week (was there?),

There has not been a new version update within the past week. The current version remains R66.28.

…it must result from syncing to the cloud. I have reset the cloud data several times, but it doesn't help.

It is possible that there could be an issue encountered when syncing with QMobile. Resetting the cloud account can sometimes resolve such issues. When it doesn't help, then sometimes deleting the cloud account can resolve it. This process requires that you do it from another data file….either create a new data file or use a different data file that you already have. When the cloud account is deleted the QMobile data is also deleted. Then when you later open your main data file, again, Quicken will create a new cloud account for it and you can then set up QMobile for it, again. You can read how to do this in this Support Article: https://www.quicken.com/support/how-edit-or-delete-your-cloud-datasets-quicken-windows/ .

But before you do that: Have you tried doing File > Validate & Repair File? I don't think it is likely that this is a data file issue but if it is then perhaps this process will fix it.

Corruption, typically, occurs on the File, not account, level … although it's certainly possible, if unlikely, that file corruption impacted only one of your accounts.

SO, start by taking a backup (just in case) and then just go thru the TOOLS, Account List menus and click ADD Account in the lower right corner of the dialog. Then move all of your existing transactions, in the old account, to the new account … disconnect the old account from download and connect the new account.

If that doesn't help, you've got the backup to restore from.