You create a new customer group. After filling in the details about the new user account, you proceed to create the user. The management console becomes irresponsive for about 60 seconds, and then console shows a pop-up error:
"Cannot read property 'code' of undefined" or "t.error is undefined"
In the Developer Tools console (F12), you can see that a PUT request to https://<dc>-cloud.acronis.com/api/2/tenants/<tenantID>/offering_items fails with "504 Gateway time out"
Issue in the product.
This issue has been fixed in Acronis Cyber Cloud 21.04.
If version 21.04 is not yet available on your DC, as a workaround, refresh the page after you see the error message; you will see that applications and offering items were turned on successfully. Then, create the user manually.