Updated to AcyMailing 8.0.0 on Joomla 4.2.7.
Uninstalled AcyMailing 5.11.2. There was an error message during uninstallation about a missing path.
Problem: trying to read Joomla articles, open existing AcyMailing template, or create a new template threw the error message, "Call to undefined function acymailing_addScript()."
Solution:
- System / Global Configuration / Logging / Log Almost Everything
Uncaught Throwable of type Error thrown with message "Call to undefined function acymailing_addScript()". Stack trace: #0 [ROOT]/libraries/src/Editor/Editor.php(141): plgEditorAcyEditor->onInit()
- Removed the AcyEditor plugin, which was part of version 5.
Result: back to normal, it seems.