I recently upgraded our server OS from server 2008 sp2 to server 2012 datacenter r2 and also

upgraded Solidworks enterprise from 2012 to 2015 and also upgraded all our seats of solidworks

from 2012 to 2015.

After doing this, 2 users regularly loose their connection to the license manager and then are forced to

save their work and then solidworks closes.  They can re-start solidworks right away with no issues

like nothing happened.

We never had this problem before.  I have done the following to resolve this issue with no success:

1. On clients and the server, created firewall inbound and outbound rules to allow TCPIP/UDP
   communications on port 25734, 25735
2. Toyed with the network card adapter settings for example power usage and time settings.
3. Repaired the installation of solidworks.
4. Did a continuous ping to the server and one time returned a timed out response but not again
   when I checked a few more times.

Anyone else having this issue or have any ideas on how to resolve?

Here is a snapshot of the message I get:

ty