Exact error message is "Sorry, your libraries didn't sync". Looking at other similar topics, other users get more specific errors.
OSX 10.15.7, latest Creative Cloud (though older versions had this issue as well).
Files sync probably works (I don't have any files to sync, but sync is showing "Up to date"), libraries sync doesn't work.
I've had this issue for a while. Paused/resumed sync, reinstalled Creative Cloud, removed local files in Library - nothing works.
first try, resetting the cc app: To reset the Creative Cloud desktop app, make sure it's in the foreground, then press:
Win: Ctrl + Alt + R
Mac: Cmd + Opt + R
if that fails, try to repair
if that fails go ahead and uninstall/reinstall per the above link
if that fails, do a clean cc install following each applicable step:
uninstall every cc app including preferences, https://helpx.adobe.com/creative-cloud/help/uninstall-remove-app.html
then uninstall the cc desktop app, https://helpx.adobe.com/creative-cloud/help/uninstall-creative-cloud-desktop-app.html
clean your computer of cc files per http://www.adobe.com/support/contact/cscleanertool.html
check for, and if available, update your os
restart your computer (don't skip this)
reinstall the cc desktop app, https://creative.adobe.com/products/creative-cloud.
if you're unable to install the cc desktop app at this stage, use an administrator account (solution 4 here, https://helpx.adobe.com/creative-cloud/kb/creative-cloud-missing-damaged.html)
use the desktop app to install your cc programs/trials
Uninstalled everything, ran cleaner app, then re-installed creative cloud. Error remains.
Repeated process again. Uninstalled everything (XD, Creative Cloud), ran cleaner app (removed everything), also just in case deleted CC Libraries from Application Support/Adobe, restarted computer. Checked processes to make sure nothing from Adobe remains - there was nothing from Adobe.
Then installed Creative Cloud again. Error remains. Installed Adobe XD, "Manage Libraries" button is grayed out.
this is from @Supriya , adobe employee:
1. Delete all folders that start with “CC_LIBRARIES_PANEL_EXTENSION_xx_xx_xx” in this location:
WIN: C:\Program Files (x86)\Common Files\Adobe\CEP\extensions
MAC: Macintosh HD ▸ Library ▸ Application Support ▸ Adobe ▸ CEP -> extensions
2. Follow the steps of Solution 2 in this article: https://helpx.adobe.com/creative-cloud/kb/libraries-panel-not-working.html
Before trying the steps - please, make sure you killed the CCLibraries process in Task Manager / Activity Monitor, as well as you have quit all Adobe related products. This is mentioned in steps 1 and 2 of the article linked in step 2, but wanted to point out, because it is important.
Thank you for getting back to me. I do not have directory "CEP" in Application Support/Adobe in neither root library, nor in account library.
enable hidden files/folders: https://setapp.com/how-to/show-hidden-files-on-mac#:~:text=See%20hidden%20files%20on%20Mac%20via%20F...!
if that fails to help, using a browser that allows popups and cookies, contact adobe support during pst business hours by clicking here, https://helpx.adobe.com/contact.html
click contact us (in the lower right)
in the chat field, type AGENT
be patient, it can take quite a while to reach a human
Hidden files are visible. Directory "CEP" just doesn't exist.
contact support. they may able to see something on adobe's end or connect to your computer and troubleshoot the problem.
I've tested idea that problem is with my account, not with files. Created new account and libraries are working again.
So looks like my account is the issue. I'll contact support.
if the problem is solved and you can post the solution here it might help someone else.