Getting system status message about contributeMode after upgrade to 5.43 when it seems like it shouldn't
This only affects master (5.43). You'd only see this on a site that was installed before 5.20 I think.
What seems to be happening is that the text version of the message template was updated in 5.20 at https://github.com/civicrm/civicrm-core/pull/15682/files#diff-5eff848ae038ac430860eb2b822aa501ad7135621221116d204c5ee8ca07fcde, but the corresponding thing that replaces updated templates in the db didn't include a reference to the text version, just the html version: https://github.com/civicrm/civicrm-core/blob/f5eb3977811d1701a3c086f4ca5b34f8d172c958/CRM/Upgrade/Incremental/MessageTemplates.php#L118
So what happens is you still get the status notice since you have an old copy of the text version in the db.
I guess the way to fix this is to add
['name' => 'contribution_online_receipt', 'type' => 'text'], into MessageTemplates.php numbered at 5.43?