PHP Parse error: syntax error, unexpected '?' in /lib/pkp/lib/vendor/illuminate/support/Str.php on line 681

Dear Sir,

I migrated my OJS 3.1.2-1 journal to another server with same domain. After migration I got below error PHP Parse error: syntax error, unexpected ‘?’ in /lib/pkp/lib/vendor/illuminate/support/Str.php on line 681

in Archives Page and Submission Page after Login

I tried every possible solution including PHP version 5.6 7 7.1 and 7.2.
I also clear cache after every php version change but not solved.
Please help

Hi @apacetech,

You are having syntax error on null coalescing operator, which was added in PHP 7.0. Please recheck PHP version that you are using, .e.g., by administration -> system information