Spectra Error thrown Class ‘WP_Theme_JSON_Resolver’ not found

Hi, since an update of the Spectra plug-in I’m running into problems. Once I active the spectra plugin the page can’t be entered and an Error is thrown Class ‘WP_Theme_JSON_Resolver’ not found. I can’t acces the dashboard either to go back to an earlier version…
the website looks without the plug-in totally different Buenos días it would take a lot of work to fix it again. Is there a solution you could recommend?

best, liska

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