Not saving Keyword, Met description anymore

Hi,

I suddenly cannot save a keyword, seo title and a meta description anymore. I enter some words, push update and nothing happens. Forms are empty, entered content disappeared. Only the slug stays.

I have the latest version of your plugin (702) of course, latest WordPress version. It’s the first post. Before I did not have any problems. How to find out the causing error? Please do not just answer something like “problems with other plugins” or “switch off your plugins”. I did not install a new plugin meanwhile.
Best regards
Hope you can help me.

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