Restrictions on bidding can be for a few reasons.
If you have had 2 or more unpaid item strikes on your account, then you will not be able to bid on the majority of sellers auctions, for 12 months.
Or, if you have just returned to your account to buy, you may have a restriction on the number of auctions you can bid on until you again show that you are paying promptly for these items.
Buying and making a prompt payment for Buy it Now items for the present time, will help lift that restriction.
@termarg35
