Edit: Just created a fresh, secondary user-account (admin) with Adobe Illustrator CC 2018 being the only software installed. And bang, everything has been super fast and lag-free as it should be! GPU-preview, regular preview, outline-view (cmd-y): all super snappy! Jaw-dropping. Reminder: we had already tried this a few month ago, but without results: fresh user, fresh installation even, etc… nothing helped. In hope to set up a fresh and smoothly working machine, we have then reinstalled the latest High Sierra. Again, with Illustrator CC 2018 being the only additionally installed software. Unfortunately THIS TIME we were back to „incredibly slow“ in regular preview and outline-view (cmd-y). What the heck? Set up a secondary user-account (admin)… and surprise: back to super snappy, again. SMC-reset, PRAM-reset, file-system set to APFS and fast forward to a couple more fresh High Sierra installations. Now the second admin-account always installs and runs Illustrator as smoothly as could be. AS LONG as we don't install anything else (anything actually) but Adobe CC. Anything else and Illustrator gets slow. NOW we are truly out of answers, @adobe : ) Please advise.
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