just installed 10.11.6. Jacsta media recorder refuses to run. the window opens, I'm told that something is wrong: cursor becomes the spinning beachball of death. In a bit, "Force Quit" shows Jacsta as "not responding". Lots of fun, maybe. Personally, I am NOT amused.
That sounds like the new OS X has overwritten Jaksta's permissions.
Can you try reinstalling it: