I have this, and having used macs since early 90s, I'm pretty sure this has not happened before, but of course gremlins do abound, but alot less in the last 10 yrs. It started end of last year (2017), I'm on OS 10.11.6. Although my mac is an iMac27" mid 2011. It is extremely irritating! Especially when Illustrator tries to open your Photoshop 500MB multilayered file that I've recently been working on in PS. Of course it takes an age to think about it...etc...several minutes while Illustrator panics and thinks and then you have stop the process only when it comes to confirmation box. Then you go to the file, info, change the default opening to Photoshop for all .psd files, globally (for the umpteenth time!), and then move on. Illustrator opens all you bog-standard jpgs! Correct the settings, and the next day it might fine (having changed the defaults), but then it reverts to ILLUSTRATOR, AGAIN!! aaagghhh! What is it about Illustrator CC?! Seems lots of people have the same identical issue. I'm a bit reluctant to push the mac to High Sierra, but maybe I'll give it a go. ('Older' macs may not be able cope). Are the boys and girls at 'Illustrator' having a bit of fun!?
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