Before lauching Indesign - quit out of InDesign - Quit out of CC Desktop - and Make sure you're signed out of CC online.
Clear your Chrome Cache - and completely reinstall Chrome
Restart
Then
Disable Adobe Fonts and Sync
Do this FIRST before you launch InDesign again.
Open Creative Cloud Desktop
Top-right profile icon > Sign Out
Quit Creative Cloud
Reopen Creative Cloud
Log back in
Go to Preferences > Services
Disable Adobe Fonts
Also disable file syncing if you don’t need it
This alone has resolved similar cases.
Purge All Adobe Licensing and OOBE Data
This is beyond “normal cache clearing.”
Quit all Adobe apps
In Finder, do Go > Go to Folder… and enter:
~/Library/Application Support/Adobe/OOBE
Delete everything inside OOBE.
Then do the same here:
/Library/Application Support/Adobe/OOBE
Also delete these (if present):
~/Library/Application Support/Adobe/SLStore
/Library/Application Support/Adobe/SLStore
and
~/Library/Application Support/Adobe/SLCache
/Library/Application Support/Adobe/SLCache
These hold license tokens and can corrupt in ways that survive reinstalls.
Rename CEP and UXP Folders
Just as Abhishek suggested, but confirm you’ve done both locations:
Rename /Library/Application Support/Adobe/CEP to CEP.old
Rename /Library/Application Support/Adobe/UXP to UXP.old
Rename ~/Library/Application Support/Adobe/UXP to UXP.old
This disables all panels/extensions and resets their state.
Use a Clean Admin User Account
If possible, create a brand new Mac user account with Admin rights. Log in there, install Creative Cloud, disable Adobe Fonts before launching InDesign.
This prevents conflicts from user-level caches and preferences.
Test Without Internet
Once you’ve purged all the above:
Disconnect Wi-Fi/internet completely.
Reboot.
Launch InDesign and see if it starts and stays open.
If it works, you can safely bet the problem is licensing handshake or Adobe Fonts.
Apps Can Cause This
In addition to Webroot and Magnet, here’s a definitive list of processes that have directly been confirmed to block or interfere with vact/ping:
Little Snitch or LuLu firewall
TripMode
AdGuard or Pi-hole
CleanMyMac
Dropbox Smart Sync / Google Drive File Stream
Carbon Black or SentinelOne
Cisco Umbrella
If you have any of these, quit them fully before testing (or anything similar).
Thanks again for this info. I'm not sure what eventually worked, it was probably a combination of proxy settings, cache and cookies like you said. It's difficult to pinpoint what fixed everything when I (and Adobe support remotely) tried all the solutions. Indesign is working again and is pretty fast, so it was probably best to remove caches, reset preferences, take care of font library and disabling adobe fonts in any case.