The following warning appears after upgrading to PHP 7.4
Deprecated: Array and string offset access syntax with curly braces is deprecated in C:\inetpub\wwwroot\moodle\question\type\wq\quizzes\lib\php\Boot.class.php on line 221
All accesses to array elements and string offsets now show a deprecation message. They will stop working on php 8.0
The following warning appears after upgrading to PHP 7.4
Deprecated: Array and string offset access syntax with curly braces is deprecated in C:\inetpub\wwwroot\moodle\question\type\wq\quizzes\lib\php\Boot.class.php on line 221
All accesses to array elements and string offsets now show a deprecation message. They will stop working on php 8.0
Related issue from Moodle core: https://tracker.moodle.org/browse/MDL-66319