Ok, so it's not a certificate problem.You may try to check the DMP configuration. Flash must be in "Read/Write" mode, FTP must be activated and configured with a password.If this is ok, try to verify te communication on ports 7777 (DMM<>DMP), 21 (FTP...

Does your DMP appears online in the DMP Manager?I it doesn't it's a certificate problem. You should upgrade your DMP FW and, if possible, your DMM as well.RegardsThiago Fausto