The tabadmin log will not be of much help in this instance. What version of tableau Server is in use? If you are using Tableau Server 8.2.x or later, than you can create the log files from the Maintenance scree in the "Admin" section of the server. Otherwise, using the tabadmin ziplogs command you can get the server log files and search for the error.
I would expect you'll find something in the VizQL logs showing what query was run when the error was returned.
Is this a live connection, or an extract? If it's an extract, did the extract refresh fail recently? If it's a live connection, has the underlying data changed at all?
That's where I would start to look for more information on this issue.
Hope that helps!
If you are not on the most recent version of Tableau Server, it would be wise to test these failing workbooks out in a test environment with the most recent version. If the issue persists, please collect logs and open a support case with Tableau by emailing email@example.com . We have seen errors like this from time to time. Do not that it would be extremely helpful for our team to have the packaged workbook in the support case if at all possible. It would also be good to know if these workbooks throw the same error when opened in the most recent version of Desktop.