Nikon NX Studio seems to grab hold of any file source such as an attached USB flash drive, HDD(s) and SSD(s).. Scanning these extra sources for NEF files takes time and can greatly slow the launch of NX Studio. NX Studio also locks external files sources such as USB Flash drives, [external] HDD(s) and [external] SSD(s).
I wonder about this behavior. I wonder if NX Studio is building a database in the background. Whatever the case, once I cleaned out the bits and pieces of failed ViewNX-i and Capture NX-D from my MacBook Pro M1 and reinstalled Rosetta 2 via the Terminal command line method, NX Studio is working correctly.
Dave