Background of the issue:
I am using WPML for a multilingual WordPress site with three languages: Polish, English, and Ukrainian. I changed the Ukrainian language code from 'uk' to 'ua,' which initially caused no issues. However, I am now facing a problem with editing posts in certain post types. I can create posts in Ukrainian for these types but cannot edit them once created. The issue is resolved when I deactivate the WPML String Translation plugin, but I need this plugin active for multilingual functionality. The issue can be seen at: 隐藏链接.
Symptoms:
I am unable to edit Ukrainian posts in certain post types when the WPML String Translation plugin is active. I receive an error message: 'You attempted to edit an item that doesn't exist. Perhaps it was deleted? when trying to edit a page at 隐藏链接.
Questions:
What is causing the conflict between WPML String Translation and editing Ukrainian posts?
How can I resolve the issue while keeping WPML String Translation active?