Some people have recently reported that they encountered models lacking the
ProjectInfo project information singleton element.
Apparently, it was possible in previous versions of Revit for a faulty or malicious add-in to simply delete this element.
That obviously causes problems for other add-ins and Revit itself, who rely on its presence.
Luckily, it is not hard to fix.
Here is the latest discussion addressing this issue:
Question: I encountered models missing Project Information, causing errors to be thrown.
Can you provide any guidance on a potential fix for this?
Can we perform a Transfer Project Standards like process to copy the project information in from another model?
Answer: You can use the copy and paste API and the CopyElements method to copy in the project information element from some other intact RVT file.
The file can also be fixed via transfer project standards.
We believe this problem to be fixed in Revit 2017 and later version, because API applications are now prevented from (hopefully accidentally) deleting the element.
I have been successful in using the copy-paste method to automate the process to circumvent the errors and add the missing Project Information.
Thanks again for the help and suggestions!