Was able to find a bug in our package installer not reporting errors properly, but the reason it's failing on your site is due your site not meeting the minimum system requirements for CB. You are currently on MySQL 5.5. CB has a minimum of 5.6 now in order to be compatible with Joomla 4. You'll need to contact your host and have them upgrade you to 5.6 and run database migration on your database.
www.joomlapolis.com/documentation/276-community-builder/getting-started/18576-technical-requirements-for-community-builder
Once you've updated MySQL you'll be able to update your install. Am also working on fixing our package installer so it'll report these errors properly as it seams like Joomla installer API is responding with an array of messages now when an error occurs.