Fatal error: Interface 'JsonSerializable' not found in /home/rpgmaker/public_html/src/XF/Phrase.php on line 5

Fatal error: Uncaught Error: Call to undefined function XF\json_encode() in /home/rpgmaker/public_html/src/XF/Error.php:142 Stack trace: #0 /home/rpgmaker/public_html/src/XF/App.php(2195): XF\Error->logException(Object(ErrorException), true, '') #1 /home/rpgmaker/public_html/src/XF.php(207): XF\App->logException(Object(ErrorException), true) #2 [internal function]: XF::handleFatalError() #3 {main} thrown in /home/rpgmaker/public_html/src/XF/Error.php on line 142