error when adding new client

Client connections are not OS specific. But if you have a total no. of 15 then only 15 are allowed to be backed up. Any one extra would give you this error.

You need more client licenses OR reduce the no. of clients being backed up. May be for a couple of clients, Uncheck "Schedule Backup" and remove them from any group.

Thanks much for replying
i tried what you suggested but it didn't work, is there any solution for this taht anyone tried and it worked?

thanks much all

You should delete the client resource to free up license. I don't believe cache cleaning is required after that. Obviously solution is to purchase additional client connections.

P.S. if you have more clients than licenses and you have some not used licenses. when the first client comes it takes the license until all licenses are used. all other clients will not be able to use the server for backup

the license is reserved once the client has used the server for backup. so if you have 15 servers and 15 licenses you have to purchase another license.
you can free up a license while not loosing the oportunity to restore when you open the client copy the client id and then delete it. afterwards create the client with the same name and the copied client id.