Civicrm local db error
The path civicrm/showevents does not seem to be a part of core. I think you have an extension enabled on your site which is creating a problem.


Disable or uninstall Event Calendar(com.osseed.eventcalendar) from Extension page civicrm/admin/extensions?reset=1.
If you can't access the extension page, try disabling this using cv command OR directly modifying civicrm_extension table in your database. Set is_active value to 0.

$ cv ext:disable com.osseed.eventcalendar

Clear cache OR rebuild the menu using civicrm/menu/rebuild?reset=1.