One of my suggestions was going to be to turn off encryption to see if it fails the same way, to try and track what may be causing this problem
Step 1. On the Cell Manager:
• Remove/Rename the "config" file from the <DP_CONFIG>/clients
• Remove/Rename the "config" file from the <DP_CONFIG>/server
• Remove "-encryption 1" from <DP_CONFIG>/server /cell/cell_info file
Step 2. On ALL DP clients:
• Remove/Rename the "config" file from the <DP_CONFIG>/clients