I'm having this same problem but with Canon Digital Photo Professional 4.15.0 not loading Print Studio Pro. DPP4 simply locks up and I have to Force Quit. This is after upgrading to Big Sur 11.6. The Plug-in Printing Option shows but doesn't load. I, too, have tried re-installing DPP4 4.15.0 and I've also reverting to DPP4 4.14, bu no luck. It's a shame because I really like Print Studio Pro.
I have the same issue with Photoshop not loading Studio pro 2.2.5 On Big Sur 11.6.
Print Studio just doesn't load even if it shows in the Plug in pannel for Photoshop. Photoshop stops responding each time I try to load Print Studio.
Any idea on when this will be fixed or a new version uploaded? I use this to print for my small business and this is really hindering my order process.
Please please help!!