I have installed a brand new 9.03.70 and I have imported messages from my test setup, also new install 9.03.70 but different computer. My test environment shows no issues when sending/receiving private messages but my production shows text with all of its html tags and throws an error in the error log.
Here is what message look like:
And this is from the log when I access the PMs:
echo !empty($info['actions_form']) ? '<div class="display-inline-block">'.$info['actions_form'].'</div>' : '';
Line 82 -- 15 hours ago
Array to string conversion