Output tool writing to .xlsm file. Cannot save Excel file.

[danthat]

I have a workflow that outputs a .xlsm file to an Excel workbook.  When the end users access the file and make changes they are unable to do so and get the following error:

I found a similar error in previous threads and the resolution was to limit the tab names to 30 characters however none of the tabs in my approach that limit.  Has anyone encountered this issue?  Searching for a solution and any assistance would be greatly appreciated.

[michelle_mathews]

@danthat  , do you have any unusual characters in your data? I've run into this before because my data contained the '=' symbol and excel assumed it was the beginning of a formula and that's what caused errors.