Chrystl on "Unable to add tags in one language with Polylang"

Hi
It's certainly a conflict between plugins.
To find this conflict you are going to make this test: deactivate all your plugins. Reactivate only Polylang 1.6.2 + your theme and with wordpress 4.0.1.
If Polylang + your theme work together you must activate your plugins one by one to find the conflict.