While exporting database from WebAdmin in Plesk, you might end up with an error as
File not Found
can’t find the file at https://xx.xx.xx.xx:8443/domains/databases/phpMyAdmin/
The issue seems to complicated but is very simple to fix.
1) Login to the server as root user from shell
2) Go to /usr/local/psa/admin/conf/
3) Open php.ini file in any of your favorite editor like vi
4) Increase the memory_limit say 512MB and save the file
5) restart plesk service
/etc/init.d/psa restart
6) Try exporting the database now which will be exported without any issues.
If any feedback, queries are always welcome!