Installation fail

Those files should not be there initially. But when you try to install, those will be generated. If your previous installation attempt was not successful or not working properly after installation then delete those and try again.

Yes those files are created in the Install.
And when they are deleted then it will force the install to run again

Did you get the install to run correctly last time ?

NO, the install never worked again after deleting it out and re uploading it
I get this msg
"The page isn’t redirecting properly

Firefox has detected that the server is redirecting the request for this address in a way that will never complete.

    This problem can sometimes be caused by disabling or refusing to accept cookies."

I even created a new addon domain, upload it and get the same thing

Just spoke with my host support
They claim to have cleared something and I was good to go
Still didn't work, same error
I reopened the ticket with the second domain doing the same thing

OK.

I deleted one site and installed wordpress (from softoulous)
Works fine

Still getting redirection error on nopcommerce

You've never seen this problem before?

You said you have deleted dataSettings.json and plugins.json from ~/App_Data folder

See if you can you force it to run install enter the URL

http://yourwebsite.com/install

I deleted everything out, uploaded the code again
Those files don't get created because it never executes the install
It just throws the redirection error
It worked orginally, but I had to delete the installation (not uninstall)
It never worked again

Could it be a server cache problem?
How do I find it with plesk?

Seems something silly like that

I dont use plesk - maybe enquire with help desk ?

What about restart the Plesk server maybe that will do it ?