When I first joined I couldn't post my map there, it didn't give me an exact restriction, it just told me that I lacked the rights to post there.
That helps. I looked and there are no specific restrictions - but the log shows you ran afoul of one of our anti-spam plugins.
Basically, you can't post URLs until you've made at least one non-URL post and been registered for 4 days. I suspect if yo try again there will not be any issue.
You should have seen a message like this:
Sorry, you were not able to save since the content contained a link<br/>
<br/>
For this Forum, before you can create content with links, you must first meet the minimum requirements<br/>
<br/>
Minimum Requirements<br/>
The number of posts you have created must exceed: 1 (Yours: 0)<br/>
The number of Likes you've received must exceed: -1 (Yours: 0)<br/>
The Like
ost Ratio must exceed: -1% (Yours: 0%)<br/>
The number of days you have been registered must exceed: 4 (Yours: 0)<br/>