Yes it can be - Manager can’t reconcile a negative BS account balance to a positively entered reconcile figure’
Does your edition of Manager have the Bank Reconciliations feature under the Reports tab, if yes, that’s good. Otherwise you are on an old edition and you should update.
Can I suggest that you delete all existing Credit Card BR reports just in case there are some data issues.
Go to Reports - Bank Reconciliations - click edit next to the CC report, scroll to the bottom and click delete.
Hopefully there should only be the one report - if there are others - delete also.
Option 1
With your latest CC statement handy, go to your Cash Accounts tab, click on the Credit Card balance - Using the date from your CCS go to a transaction with a date just prior - if the CCS is May 31, then the last transaction in May - record the balance next to that transaction - all things being equal it should equal the CCS balance - if the balance is in red then its a negative figure.
If the balances don’t match then this could be the start of your problem - go to Option 2
Now go to the Reports - BR - click new report - enter the Statement date - select the CC - and click Create.
Click on View next to the CC listing and enter the balance, with minus if applicable, click Update and the Reconciliation Report will appear.
Option 2
If your CCS and Manager account balances aren’t equal then there is a data mismatch which needs to be sorted. Calculate the difference the two balances and record it.
You mentioned above that you want to reconcile from 2015, so go to your earliest statement of 2015 and note the starting date and opening balance. Go to your Cash Accounts tab, click on the Credit Card balance - Using that date from your CCS go to a transaction with a date just prior - if the CCS is Jan1, then the last transaction in Dec - record the balance next to that transaction - does this equal the opening balance - if not, is it the same balance variation as before?
If its the same variation then that needs to be fixed, if its a different variation then there is a mismatch of data both before and after Jan 1, 2015. Regardless of the variation situation until there is a matching balance between the CCS and the Manager CC account - you will “never” be able to reconcile,
You can’t, as you suggest, just pick a starting date/balance and commence reconciling from there as that only hides the flaw rather then resolving it.
So you could either requests copies of the missing statements from 2013 or as at Dec 31, 2014 post an adjusting transaction equal to the Jan 1 variation. Then do a reconciliation as at Dec 31, 2014. Then complete all subsequent reconciliations in alignment with CCS dates & balances