Hi Matt,
I am having the exact same issue with 1.7.7.4. I have installed two or three times now, and I get the same issue every time. As it so happens I have an account with a different hosting provider, and just for sh*ts and giggles I tried to install there. And what would you know.. it worked first time.
so my first attempt was with inMotion hosting, in the US, If I look at their one click application installers I see that they only have prestashop 1.6 on offer. My different host (VDX in the Netherlands) offers 1.7.7.4 as a one click application (though I am not using the one click, I was just interested in what was on offer), also other small differences leads me to believe that VDX is more up-to-date than inMotion. So perhaps the issue lies with the hosting provider. I wish I could tell you what the solution is, but these are just my findings.
Regards,
Dave.