Is there a possibility to disable the TextChat function for users?

This article describes how to disable the TextChat feature.

For individual users

Yes, in the UCServer Administration => User Administration => Users => Properties => Services, the checkbox "Send short messages" has to be removed.

Additional permissions

Please note the additive authorization system of ProCall Enterprise: A right given to a user (e.g. via a group) cannot be revoked via the authorization at another location (e.g. user).

Global for all users

Yes, in the UCServer Administration => Menu bar => Tools => Basic Services, the chat can be disabled globally.