Had an error over the last few days on the Merchant Centre with our feed.
We recently upgraded our server to a newer PHP version and as a result we had a few issues that needed resolving, one of which being the feed tool which we had to change.
The feed it outputs seems to be correct in nature i.e. formatting/fields etc however when google tries to access the feed it fails and gives out a response code of 403 in the File Errors section on the Merchant Centre.
We can view the feed from multiple locations and it appears to be formatted correctly in different browsers.
The directory the feed sits in is the root and there are no authentication steps required.
Not really sure where to start with such a vague error (nothing in the logs either) =(
Also tried without firewalls/mod sec off and without robots.txt.