By "accident", I discovered that a faulty database filter in a trace configuration can crash the server. Tested with a few days old Firebird 2.5.2 Snapshot SC 64-bit on Windows. The used database filter doesn't make sense, but because it crashes the server, I thought reporting here makes sense. In our product, when the user creates a new trace configuration, the tool defaults the database filter to something like that:

<...enter database regex string here...>

so that the user is somehow "forced" to enter a database filter. If the user leaves this entry as is, upon starting a trace session, the server crashes. As said, the database filter doesn't make sense and probably will never be used that way when e.g. writing a trace configuration by hand, and I also can change the default value above, but IMHO the server shouldn't crash.