No, other members cannot tell you why
What did it actually say (it would not have said 'you can't do bidding' )
The most likely reason is the seller you are trying to buy from has blocked you
Maybe they had already looked at your feedback left for others (as people here will)
Do you also have unpaid items?
Do you have a PO Box?
Have you bought from the seller before?
It is very unlikely to be a site issue