Translate not working after update

Hello,

After an update I have an issue with the translation Everything is fine but when i try to add language and shows only on specific language its not working . When I click save the language display selector will disappear after refresh it will back again but it will not take effect any changes.

Please help.

I try Troubleshoot with this methods:
1: I try to deactivate but when I try to deactivate I have a fatal error
“Fatal error: Uncaught Error: Call to undefined function pll_register_string()…..”
I try to remove pll register in function it worked but still problem persist. And from the previous version i have no problem with my pll register code.

2. I didn’t uninstall yet Im not sure if i will lost my files or no.

THANKS

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