Hello,
Sorry for the delay in answering.
1) Where do you see information that your support is expired? Please provide URL/screenshot.
2-4) Try to disable all the third-party plugins (including cache plugins), that do not come bundled with XStore https://www.8theme.com/documentation/xstore/plugins/included-plugins/ , clear cache of browser, and check how it works then.
5) https://www.8theme.com/topic/error-functions-php-on-line-5313/
Regards