@ieo shared a link to the previous version:
See the link to previous versions in my above post, if you need 6.7 for mac use https://download.manycam.com/thank_you_page/mac-6.7
Don’t forget to delete settings (look for corresponding checkbox) when you ininstall manycam 7.0 (recommend to uninstall it before installing old versions)
However, I fixed some of the issues by deleting all my presets and creating new ones. Try to do a clean install (completely uninstall the software and install it again from scratch).