I am incredibly annoyed that when I click Save As lately, everything greys out and I get a freeze. This is not good. Please fix this!
Sorry for the trouble. What is the exact version of Premiere Pro? Steps: FAQ: How to find the exact version of Premiere Pro you're using?
What is the location to which you are saving the project file?
Just for a test, change the name of the project file and check the issue.
When using Save As, always change or increment the name of your project. Do not name the project the same name as the original and attempt to save over that original. If your project was called "Man Bites Dog," using Save As, title it as "Man Bites Dog_01" or the like. Please try that.