Keynote error opening file "operation not permitted"
I have an iMac (iMac17,1) running Big Sur 11.5.2 and Keynote 11.1. After I have opened 2-4 Keynote files over a span of 1-2 minutes, I then get an error anytime I try to open an additional Keynote file. The error reads "File Name" can't be opened right now and then "Operation not permitted". If I close Keynote I can open 2-4 more files and then the behavior returns. I have deleted and reinstalled Keynote. I have deleted the Keynote preference file, as well as the support files in the ~\Library\Containers folder. All to no avail. I also have 2 other machines displaying this behavior. I am at a loss as to the cause at this point. Has anyone else experienced this behavior and found a solution?