Good evening,
I'm currently running 1.6-beta with php8.1-fpm and all appears to be working properly except the Allow button (for email-embedded HTML content) is missing and the HTML content of emails is broken (see attachment). When rolling back to 1.5.2 on the same system, all works properly. I appreciate any suggestions anyone may provide. Thank you for your help!
Self-reply here for others who may encounter this... somehow through the upgrade HTML content display was completely disabled (Settings - Preferences - Displaying Messages - Display HTML)... perhaps user error here. Enabling this setting has resolved my issue.