Fatal error: Map is broken in frontend and not editable in backend

I just updated to WordPress 4.9.4 and Google Maps Easy 1.8.7 and the map is broken in the frontend and not editable in the backend! related to https://supsystic.com/topic/cant-open-edit-maps-google-maps-easy/

Error Message in frontend is:
https://bikesisters.net/radpartnerin-finden/

Fatal error: Uncaught Error: Call to undefined method marker_groupsModelGmp::getMarkersGroupsByIds() in /www/htdocs/w014c1bf/bikesisters.net/site2016/wp-content/plugins/google-maps-easy-pro/custom_controls/views/custom_controls.php:20 Stack trace: #0 /www/htdocs/w014c1bf/bikesisters.net/site2016/wp-content/plugins/google-maps-easy-pro/custom_controls/views/custom_controls.php(4): custom_controlsViewGmp->getCurrentMapMarkersGroups(Array) #1 /www/htdocs/w014c1bf/bikesisters.net/site2016/wp-content/plugins/google-maps-easy-pro/custom_controls/mod.php(39): custom_controlsViewGmp->showCustomMapControls(Array, false) #2 /www/htdocs/w014c1bf/bikesisters.net/site2016/wp-includes/class-wp-hook.php(286): custom_controlsGmp->addMapBottomControls(Array) #3 /www/htdocs/w014c1bf/bikesisters.net/site2016/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array) #4 /www/htdocs/w014c1bf/bikesisters.net/site2016/wp-includes/plugin.php(453): WP_Hook->do_action(Array) #5 /www/htdocs/w014c1bf/bikesisters.net/site2016/wp-content/ in /www/htdocs/w014c1bf/bikesisters.net/site2016/wp-content/plugins/google-maps-easy-pro/custom_controls/views/custom_controls.php on line 20

Please help!