Error chat not found

If you try to publish a post and receive the error "Unable to publish post" and see the phrase chat not found in the details, something like this:

the reasons may be the following:

1. the channel/chat to which Telepost was linked has been deleted, or the bot has simply been removed from the admin list.
2. the Telepost bot lacks permission to edit channel information (the bot will also use this permission to check for the channel's existence):

Solution

Please check and fix the following:

1. the channel/chat actually exists (not deleted), and the Telepost bot has been added as an administrator.
2. the bot has sufficient rights: at a minimum, it needs permissions to edit channel information and manage messages.