P: LrC 12.2.1 fails to start/launch or is extremely slow launching.

@coreyaj write, "I do not have the metrics.json file on my system."

Triple-check by following the precise steps here to avoid various gotchas looking for the file:

https://community.adobe.com/t5/lightroom-classic-bugs/p-lrc-12-2-1-fails-to-start-launch-or-is-extremely-slow-launching/idc-p/13695275/page/6#M41952

I'm in a similar boat as tigger4325, I've updated, uninstalled ans reinstalled everything, and LrC will not launch at all.  I click the button, the loading window pops up for half a second then dissapears.  New Lightroom will run, just not Classic.
I do not have the metrics.json file on my system.
I posted this about a week also  - Thanks.

Apple M1 Max
32 GB
Ventura 13.0.1

Mac user here. This fix (removing metrics.json file) worked me as well. Hope it won't recur and/or that an update will avoid the need for this workaround. Many thanks to the person who figured this out.

That workaround fixed the problem. Thank you!

thank you so much...that worked! 

See my previous reply above:

https://community.adobe.com/t5/lightroom-classic-bugs/p-lrc-12-2-1-fails-to-start-launch-or-is-extremely-slow-launching/idc-p/13705898#M42083

@courtneym70595214, Deleting "metrics.json" can be persnickety-- try the precise steps here:

https://community.adobe.com/t5/lightroom-classic-bugs/p-lrc-12-2-1-fails-to-start-launch-or-is-extremely-slow-launching/idc-p/13695275/page/6#M41952

I use Lightroom classic on my Mac and have not had too many issues with it until yesterday when it just stopped opening. When I click on it initially it looks like it might open but then the spinning wheel of death appears and it never progresses. The force quit box says Lightroom is not responding. I have tried many of the "fixes" but am not all that tech savvy so not sure if I'm doing something wrong. I have tried to reset the preferences using the shift-option thing but also get the spinning wheel of death and have to force quit it. I have tried to do it manually by looking for the com.adobe.LightroomClassicCC7.plait but I can't find it. I have logged out of everything and signed back in. I have tried to uninstall everything and reinstall. I have tried to open it from a previously saved back up. I have looked for the metrics.json file but don't have one to delete despite knowing Lightroom is not open. I have installed a previous version (12.1) of LrC and that didn't work. I'm at a loss. Help!  

@Tessa288894707bf6  The file is supposed to be there. It is just supposed to be small <100KB not big > GBs.  You need to start a new thread as your issue most likely unrelated to this thread.