UPDATE: If you upgrade to Illustrator CC 2015.1 / Illustrator 19.1 you will not have to run through the copy paste process. Hi, We have released a patch 19.0.1 that fixes the issue being discussed on this thread. Please apply the patch from your creative cloud application. The creative cloud application checks for update once a day hence you may not see the update right away. If you want to force the check for an update early please logout and log back into the Creative Cloud application. All new files created with this build will not be slow to open / edit. The files that have already been created earlier using Illustrator version 19.0 would still continue to open slow. Here is the workaround for such files Apply the patch 19.0.1 Open the file that is exhibiting slowness (it will still continue to open slow) Once the file is open please unlock all layers/objects and do a Select All followed by Copy Create a new document Remember to use the Paste Remember Layer in the Layer’s panel Paste the content You should now see all the objects and layers from your previous file Save this new file and continue to work This new file should not exhibit the slowness as earlier. Link to the release notes of 19.0.1: https://helpx.adobe.com/illustrator/kb/illustrator-cc-2015-crash-bug-fixes-19-0-1.html Regards, Ashutosh On Behalf of Illustrator engineering Team
... View more