This is a problem with the configuration of php and/or the web server. contact
your hosting people.

neo_ted wrote:

Instead is it just possible that I get a new server?

ayg wrote:

You need to have a PHP configuration set up with open_basedir off. Most hosts
presumably run such a configuration, so it may be that switching will get you a
host that doesn't have the restriction. You could ask before you buy. But in
any case, this isn't something we can do anything about.

Generally open_basedir will work, but this seems to be a particularly broken
configuration.

1. The web root seems to be using an UNC path, which seems very likely to break

things
with PHP and/or the web server and/or other software.

2. The open_basedir path appears to be "." (current directory) which:

a) will inherently not work with the installer
b) seems very likely to break the rest of the wiki
c) seems extremely fragile when mixed with UNC paths

If you operate the server yourself, I would recommend disabling open_basedir
and going from there; if you don't operate the server, contact your hosting
provider and see if they can set open_basedir to an actual directory value (or
remove it)