OutputWriter php warnings - no buffer to delete

ob_clean() is being called without ob_start. It maybe you want to keep this is case any scripts with php closing tag followed by whitespace
Logged warning message is
ob_clean(): failed to delete buffer. No buffer to delete at /vendor/dhtmlx/connector-php/codebase/Dhtmlx/Connector/Output/OutputWriter.php line 25

I suggest a simple line fix, just to prevent these warnings being logged

Connector/Output/OutputWriter.php line 25, change from @ob_clean to

if ( ob_get_contents() !== false ) @ob_clean(); // only clean if a buffer actually exists

Regards from UK