Blank Workbook in Toad Data Point

We are currently using (64 bit) Toad Data Point Workbook. We have had it happen twice now where a workbook is saved and you can see there is data by looking at the size but when the workbook is opened it is blank.

Blank, as in, not seeing any workflows/steps, or blank regarding the data from these steps?
If the workflows are there, are you getting any data at all for any or the workflow queries and their steps?
Has something changed regarding connections or data?
When you re-execute the Workbook, does the data get refreshed?

There were some issues with Workbooks in previous versions of TDP that were resolved in 5.1. Can you upgrade to 5.1 and see if the issue is resolved?

The workbook opens with just the Workbook pane on the left with no Workflows/steps. I can see by the size of the file it is there but when it is opened the workflows/steps are not visible at all so there is nothing to execute. We can not upgrade to 5.1 yet. This is something that has to be vetted by our IT staff first and then they push out a package after the new version is tested by various staff. We are currently using bit). Can you tell me what issues were identified and “fixed” with 5.1?