I changed my privacy settings to friends only a few days ago and decided to revert that change back to public. When this happens, a privacy notification on SourceOP appears and the problem resolves itself after a few hours. However, this is the first time I've had a low steam level notification -- likely to do with the privacy settings change. I have a steam level of 32.

It looks like Steam Community is having problems loading data because of the summer sale.

Low Steam Level Notification

In order to use the SourceOP forums for trading, we require users to have a steam profile level equal to or above what Valve uses to discourage alt accounts from farming objectives during Steam events, see the FAQ for additional info (CURRENTLY STEAM PROFILE LEVEL EIGHT).

Once your profile meets the posted requirements, please make a thread in the support section to have your account restriction lifted.