Events Calendar is crashing my site

Hi everyone. The Events Calendar plugin keeps crashing my site. Today I deleted my original plugin and downloaded and installed a new version. As soon as I hit “activate” my site goes down. Maybe someone can help me? Here’s my info:

WordPress version 5.9.3
Current theme: HappenStance (version 3.0.1)
Current plugin: The Events Calendar (version 5.14.1) (This is the old one)
PHP version 5.6.40
Error Details
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An error of type E_COMPILE_ERROR was caused in line 12 of the file /home/davi9405/public_html/stonebridgeevents.com/wp-content/plugins/the-events-calendar/common/src/functions/conditionals.php. Error message: Default value for parameters with a class type hint can only be NULL

• This topic was modified 2 years, 6 months ago by Jan Dembowski. Reason: Moved to Fixing WordPress, this is not an Everything else WordPress topic

The page I need help with: [log in to see the link]