For running J!5.1 you must https://fabrikar.com/forums/index.php?wiki/update-from-github/ or include the new file manually https://fabrikar.com/forums/index.php?threads/joomla-5-1-and-fabrik-cannot-find-files-error.54473/post-285151 See also Announcements
Please see our announcement here.
It's showing the placeholder, it can't show any data in the popup because it's taking the data from each selected row.The placeholder is not filled in while viewing the email before it is send. (as I thought it was)
Try a new GitHub update. There was an issue addressing ? in URLs.github (30-03-2020)
Thanks for your answer!It IS working with SEF enabled. It was only some time between GitHub updates where it was not. This didn't affect official Fabrik versions.
1. There is popup with spinning loaderWhat "doesn't work"? No popup, popup with spinning loader, not sending...?
Was it working with older versions?
Which php version?
The list email plugin is "sensitive", any system error/warning/notice may break the expected JSON string. Check in your browser dev console for JS errors in the console tab and also in the Network responses.