Error: /api/sync returned disallowed changes

[sentry]

We've received several of these errors related to channelsets, in which the user tries to delete one. The disallowed change looks like the following:

[
  {
    "key": "cecc316cc8424ed6941598dfc3aeeae8", 
    "rev": 9, 
    "table": "channelset", 
    "type": 3
  }
]

---

Sentry Issue: STUDIO-FV5

Error: /api/sync returned disallowed changes
  at callback (./shared/data/serverSync.js:111:33)
  at handleDisallowed (./shared/data/serverSync.js:105:7)
  at debouncedSyncChanges</< (./shared/data/serverSync.js:312:9)