[Mister_Magotchi]

Is the temp.xml the only contents, then, of that cache folder?

The first error you were seeing, "Error replacing cache with fresh XML content temp. file.", as I did two operations at once at that point in the code, could mean either than the permanent cache file (like 1576325.xml) existed but couldn't be deleted, or the temp. cache file (temp.xml) couldn't be renamed to the permanent name (like 1576325.xml).

Basically, on each iteration (each Steam group), cURL grabs the XML for the group, saving it to temp.xml. If it successfully gets some data, it's supposed to delete the old cache file stored for the group (like 1576325.xml), and then rename the temp.xml to that name.

In your case, cURL is certainly successful in getting data, but there's a problem in that operation, and my main guess is that something I'm not aware of is keeping the temp.xml file locked. If it were a problem deleting the other cache file (like 1576325.xml), then you wouldn't be seeing the second error you were seeing ("Error reading XML data...").

If you manually try to rename the temp.xml file while the server is running, does Windows allow you to, or is the file locked?