I found the bug. It was the WooCommerce Multilingual plugin not booster. Sorry! You can close this topic!
I update to 5.2.1 but this issue isn’t fixed. I need a sulution! Please help!
I get the same error message as ideje but I only use the multicurrecy and WPML modules. I need this modules, because the complete shop is based on the multicurrency module, so I couldn’t deactivate it. Do you have an idea to fix the problem for this module? The shop will go online asap and I need help urgently