Monica

Problem:
When upgrading old system to current releases, the WPML > Languages area is blank.
Solution:

Here is what I had to do:

1. Complete the SSL activation to eliminate the issue of mixed content errors

2. Manually upgrade the WPML Plugins to their latest versions

3. Run the following tools in WPML > Support > Troubleshooting
- Clear cache WPML
- Reset Languages
- Cancel in-progress automatic jobs

4. Use ADMINER to remove all entries from translation jobs related tables

5. Re-add the language: kh-km
used wordpress locale: kh

6. Remove zh-hans and all its data

Relevant Documentation:
None