Mesmerize Page Builder Missing & Other Errors

Hi All,
I just started using Mesmerize theme for my website, it has the best layout.
It was working all great until I was trying to change the credit footer and then the whole footer disappeared and after reverting the changes it wouldn’t go back to the beginning template. I tried re-installed/activating everything, the theme etc and then the customiser stayed on the loading page and wouldn’t progress.
I gave up.. and started again..
I deleted all the work and started from scratch.
Now the page builder is not showing at all. I can still customise the homepage through the customiser, but the page builder button is missing on all pages.
I disabled all plugins and then reactivated just the mesmerize companion plugin and still nothing.
Please help me!

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