Update from the support:
„As per our discussion, I checked with my escalations team and confirmed the information you requested. The issue you’ve been experiencing, along with several other customers, has been identified by our engineering team. The problem is that the macros couldn’t be run when using Project Online from the enterprise global template.
The new update released in Office includes a real-time virus check on the VBA code. If it detects something suspicious, it stops the code execution, which is why the error in the dialog appears. In this case, the scan is being overly cautious with the FileOpen and FileOpenEx methods. If you open a local file, you’ll find that they work because it’s not connected with the Enterprise Global Template.
The DWORD added in the Regedit ensures that the virus check from Office code makes the macros a trusted source and allows them to execute properly. Without this, the Project will add the macros to the cache folder only. Hence, we had to add the key in Regedit.
If you’re not willing to add the keyword in Regedit, you will receive a new update for Project in the next few weeks that will resolve this issue. Other than this, there is no more information to share with you, as our engineering team has redacted the details to avoid potential security violations.
„