Hello, we have one customer using FreeBSD and Firebird 2.5.4

It works fine till this week when firebird crashes twice.

In Firebird.log i found this text

verbis Mon Sep  5 22:44:01 2016
Operating system call semaphore.h: release: sem_post() failed. Error code 22
verbis Mon Sep  5 22:44:01 2016
SRVR_multi_thread: shutting down due to unhandled exception
verbis Mon Sep  5 22:44:01 2016
operating system directive semaphore.h: release: sem_post() failed
Invalid argument
verbis Mon Sep  5 22:44:01 2016
SRVR_multi_thread: forcefully disconnecting a port
verbis Mon Sep  5 22:44:01 2016
Shutting down the server with 35 active connection(s) to 1 database(s), 0 active service(s)

Then we update firebird to version 2.5.6 and i have no information about new crashes.

Does anybody knows what happend ? What should we do to prevent this error in future?

Thank you all, Tom