Can no longer open alternate Photo libraries
I created a secondary Photos library as a way to archive older photos to "cold storage". Since the last MacOS patch (Big Sur 11.3), I can no longer open this secondary library. Thought that I might be an issue with my external drive, so I tried creating a new library, on the local drive in the same folder, using the same method, previously employed and I receive the same error message when attempting to open. Mind you, newly created, empty library on local hard drive, will not open:
I found the solution to the above issue!! If I copy my alternate photos library to the same folder where my system library is stored (/Users/username/Pictures), it opens without issue. If I move it to any other location, even a folder within the above named folder, I get the same error message above.
Apple should update documentation clarifying this limitation/requirement.