There was an issue with one of the download server's earlier this week which has been resolved. Are you still seeing the error message?
For your future reference, features regarding the basic/premium license are on pages 10 and 11 of the product guide.
I do not have the premium licence. I do not see in the sections that you outline where it speaks about the ability to download the DB and categorize in the reporter.
I am still receiving the error. I receive a message that says the download has started but then I receive an Email that it failed. I would suspect that if downloading was a function of the premium licence that the download button would be grayed out and not allow selection.
You don't need a premium license for categorization, but you do need to have a valid serial number to download the URL database used for categorization. Typically the serial numbers start with SF or WE and are 16 characters long (WExx-xxxx-xxxx-xxxx). You don't want to post your serial number here because others could use it, but if you send me a private message, with your serial number I can verify that it's valid.
So to use categorization,
1) Find your serial number. SFxx-xxxx-xxxx-xxxx
2) In Web Reporter, go to : Administration > Options > Categorization
3) Check the box to download the TS Web Database, and enter your serial number
4) Enter proxy settings if you need them, then save changes.
5) Click Download Now.
Enable categorization on your log sources
6) go to : Administration > Setup > Log Sources
7) Edit your log source, and go to the processing tab.
8) Check the top two boxes for categorization and reputation.
After the download of the URL DB is complete Web Reporter will begin categorizing any URLS not already categorized in the logs.