A few things I noticed:

1) With rare exception, it only seems to happen outside of business hours.  Usually in the middle of the night, but sometimes shortly after closing or just before opening.  In the 16 instances in May so far, it only happened during business hours twice.

Here are the dates:

5/2 10:02am (Saturday, closed)

5/4 11:32am (during business hours)

5/4 4:17am

5/8 3:03pm (during business hours)

5/9 1:42am

5/10 8:49am (Sunday, closed)

5/10 10:13am (Sunday, closed)

5/10 9:11pm

5/12 11:46pm

5/12 4:16am

5/14 2:01am

5/15 3:38am

5/17 7:12am

5/24 2:28am

5/27 5:25pm

Our applications don't generally run any background processes at night, so I'm wondering if Firebird runs some sort of garbage collection or something when the system isn't being used, which has a bug that is causing it to crash.

2) When the Abnormal Termination happens, it seem to occur several times within a few minutes of each other.  Generally, it will get an Abnormal Termination, start again, crash again, start again, etc.  This happens about 2-4 times before it stays running.  Often after that it will run for 20 minutes to an hour, then happen again.  Note that in my date/time log above, I only included each "grouping" once, and didn't list it again the same day unless they were at least several hours apart.

So, I'm wondering if some Windows update started causing this, or started exposing a bug somewhere.

Here are my server details:

Windows Server 2012 R2 Standard

Running under a 

Running Firebird 2.5.1.26351

Any help would be greatly appreciated.

-Joe