Working on a computer that had Project 2013 and Office 365 Business installed the following error was displayed when trying to generate Visual Reports within Project
I resolved the above error by copying the Excel.exe file from the Office folder (C:\Program Files (x86)\Microsoft Office\root\Office16) to the Microsoft Project Folder (C:\Program Files (x86)\Microsoft Office\Office15\)
However, The Excel 2003 error is now replaced by “An Unknown error has occured”
I applied all Project and Office updates, set both programs to run as administrator but the error still occurred.
Looking at the versions of Project and Office that were installed I could see that Project was installed via MSI whereas office was a Click-to-Run product.
I Uninstalled the MSI version of Project and installed a Click-To-Run version and Visual Reports then ran fine.
There is obviously a compatibility issue between the Click-To-Run and MSI versions of Project and Office. Luckily we had access to a Click-To-Run version of Project. If you come across the same issue the only fix may be to use ONLY Click-To-Run OR ONLY MSI versions of Office and Project.