You should use a debugging tool to fetch detailed crash logs and report it to
https://github.com/otland/forgottenserver
Quick tutorial (LINUX):
First install gdb. If you're running debian-alike (like Ubuntu, Debian, etc), you can do this with
apt-get install gdb
(use sudo if ubuntu)
Now load TFS into the debugger (Make sure your are in OT directory)
gdb ./forgottenserver
You will see 10-20 lines as gdb loads the server binary into memory, followed by the prompt:
(gdb)
Now type: run
(gdb) run
And the OT should start.
At this point your server is running.
Now you just wait for the server to eventually crash, you will see something like this:
Program received signal SIGSEGV, Segmentation fault.
After the crash gdb will wait for you to type a command. Now to get to the actual useful part which makes it easier for TFS developers to fix, type "bt full":
(gdb) bt full
This will dump loads of information which the TFS devs can use to find the error. Copy this, open an issue on their github page, send it there and they will probably fix much quicker than usual.
When you have reported the bug, you can quick gdb with "quit" command.
(gdb) quit
And you are done. Repeat these instructions to start it again and look for another error.