I want to export a survey for import on other website.
When clicking on export I get a blank page, when error reportin on I get these lines:

Warning: require_once(PEAR.php): failed to open stream: No such file or directory in /home/public/sites/domainname/components/com_cjlib/lib/misc/Serializer.php on line 53

Fatal error: require_once(): Failed opening required 'PEAR.php' (include_path='.:/usr/share/php') in /home/public/sites/domainname/components/com_cjlib/lib/misc/Serializer.php on line 53

I have joomla 3.9.24 and CS  5.5.9 and cjlib 3.0.11
How can I solce this error?
Thanks in advance