Links connect transactions together. For instance a customer payment is linked to an invoice. What's happening here is some links have been lost somehow. So it is data corruption at that level though often it doesn't matter much as the transactions in question may be a long time ago and no longer relevant to current year operations.
Every transaction has a "RecNum" which is short for record number. Its just a unique number to a specific transaction. The "linkRecNum" is an example. But the one you really are interested in here are the m1, mtOne, mTwo, etc.
You can find the transactions on QuickBooks Mac (if they are still there) by using the Search function. Command-F will bring it up or click on the magnifying glass in the toolbar.
To find a record 1533024 by recNum, type
@recnum = 1533024
in the search bar.
You'll see any found information appear. Note that recNums are only unique for a particular type of information. For instance if I search for recNum 2 in the sample product file I'll find a vendor with that number but also an item and an account. With links you are looking for transactions that match.
If you find do find the transaction explore a little more and look at all of the ones that are reporting errors. The best way to fix them is to first make a backup of your company file (_always_ do this) and then take screen shots of the transactions being sure to capture all the info (you could also print them but sometimes info doesn't show on print outs - like item cost, etc). Then delete the transactions and reenter them by hand. That will often fix it.
But again if they are old and no longer relevant you may just want to leave them alone.
Finally be aware that item prices can change over time and if you re-enter them you may get a different price than when they were originally entered. Same with customer and vendor addresses, etc. In that case be sure to override the default entered value to match the original transaction.
