server goes to it's error page

I have completed the steps for installation up to the page requesting System settings. I fill that in, click on SAVE and it goes off to my server but gives me an error default page. My server host says that it is a coding error.

Site URl data:

Directory path:

View: default

I have tried deleting the "install.php" and also resetting the permissions on the Data and Public_html directories (now back with full permissions) to no avail.

Nothing is being written to the Data directory

Can anybody help please?