I've had issues with Free-space pages before (with punctuation), with the same error message.
What I did was create a new Free-space page with the name without punctuation - made it shorter - and then uploaded to the new one, changing the Page name to suit afterwards (as that's how it appears on the page title) which does not affect the Space name.
Then I merged the old Space page into the new one. That got rid of the redundant page, and I could keep all the information I already entered.