Sometimes, after Excel runs into an issue with an add-in (including but not specific to FuseDocs), you may receive this error message when attempting to open an Excel document:
Workaround from Microsoft
To correct this setting, follow these steps:
- Select File > Options.
- Select Advanced, scroll down to the General section, and then clear the Ignore other applications that use Dynamic Data Exchange (DDE) check box in the General area.
- Select OK.
This problem may occur if the Ignore other applications that use Dynamic Data Exchange (DDE) check box in Excel options is selected.
Read more about the Microsoft solution here
Once the fix above is applied, the issue should be resolved until Excel encounters another issue.
If you experience this issue repeatedly, it may indicate an issue with FuseDocs or some other add-in. If so, please log a support ticket.