Sync errors all over the place related to ZSC key

Sync errors all over the place related to ZSC key

We're getting messages all over the place:

The sync "xx" has been disabled as the ZSC key is invalid. Update the valid ZSC key and initiate sync.

These sync's have literally been up for years.    Is there some new change in Zoho Campaigns that I missed or does anyone know what's going on here?