Thanks for the answer, I don't use API, I enter the orders manually but they can be more or less one hundred some days (and I cancel some). Maybe it was a bug...Otherwise until then very satisfied with Bitfinex order execution.

Problem solved a few minutes ago (still I don't know why I had it, is there a limit on the number of orders placed in a day?)

Since this problem I have the message "you can not place new orders" when I try to create an order, for info I have less than 50 orders placed and my position was very small (0.02 BTC) when the problem started. Any idea?