Help, errors on event servers

We're having some problems with File System factory on our replica servers
which are serving as event servers. Each time we load the File System
factory NLM it abends the server (abend log shows FSF is the culprit) and
then on the screen we see the following:

Proxy CRC check required
Unable to open connection to server rc=44926
AST Mainlinethreadlogin failed err=16

We have made to changes to the product and just started to see this about
two days ago. Any ideas?