Just an update on issue, it appears that LR locks up processes now after 2 or more commands ie Open, Import Locked, you simply cannot do anything with it.... Urgent help is required now...as I cannot fix or work any further with it...
Just another update, I have tried to blackout from 15.2.1 back to 15.2 and I keep getting a messaged U44M2P7, I have also notice that the error is not only limited to Canon Files, it is also not allowing me to do anything with NEF as well. Massive GUI issues, non responsive. I cannot copy files to another folder either, comes up with error dialog box.
Please can some give me some support here soon
I have spoken to AppleCare, who have kindly looked at my machine, checked & cleared Caches, verified and First Aid'ed the SSD / HDD & confirmed that everything is running on EI Capitan as they would expect. The issue is most defiantly with the last update from Adobe in my case, unless Adobe know otherwise...
Another update. I have resolved my LR 15.2.1 issues and appears to be working fine now.
Advice for anyone having major GUI issues LR 15.2.1 running on Apple MacBook Pro Retina 2013 edition with Apple El Capitan in relation to CR2 files. Symptoms started after upgrade from 15.2 CC.
OS X Symptoms: Finder Related - If you have slow full resolution render in finder, ie select a RAW image (not jpeg) & press spacebar to preview image, if the image is around 15-25mb & if it takes over 20-30 seconds to load full resolution with excellent clarity or you get the rendering cogs, then it might be that your library caches are chocked.
Adobe LR Symptoms: LR 15.2.1 - GUI not responding, sticking, non responsive on CR2 files once file cache has been read or changes made.
Depending on how clean your machine is ie Contact AppleCare to help you clear down System & User Library Cache data, then do a HDD First Aid with OS X Utilities.
Restart your machine and then try the Finder Preview again, my now taken 10-15 seconds for full render, which is normal for such a large file. Also somehow the cleanse to cache has also dramatically improved the LR15.2.1 as well.
In regards to LR 15.2.1 CR2 files are reading better again and I can see the updates in near realtime. Also look at the threads for GPU performance issues as well, as I switched mine off, restarted LR & Closed Completely down Laptop and restarted again enabling the GPU box and that may of helped also.
Further to the slower Finder preview rendering, to fix this I can re-install El Capitan to further fix my issues if I want to, however I have decided not to at this stage, simply due to the risk & maybe requirement of a full hard reinstall, which would mean data loss and I do not want that, without doing a backup first. I am happy to carry on working as is until I have time to backup and do the full re-install, which I will do in my local AppleStore..
Sorry not a clear answer to my own resolution or steps to follow, however one or more of these have seriously helped me out today...so I hope it helps others too facing the same or similar issue