[SOLVED] Problem - Native Export metadata - HTTP ERROR 500 (3.1.1.4)

Software Support
1

Hi, everybody.
Aftermigration from 2.4 to 3.1.1.4 don`t working Native export metadata.
I see: HTTP ERROR 500

The second problem, after Upgrade, the system does not link articles to PDF files, despite the fact that the entry is in config.php.

2

This topic is SOLVED.
I upggraded from OJS 2.4.8 to 3.0.0.0, after from 3.0.0.0 to 3.1.1.4. It works.