That means that your code was failing some tests but the testing framework doesn't know how to print vectors of pairs. I added a function to do that so you can exactly see your errors.

also your code potentially accesses array elements out of bounds, you're not checking the index in your first loop

one error that i see in your code is that you dont report the count in case of empty input; that might cause some undefined behavior somewhere in the tests suite

Erlang errors are cryptic but I notice "... failed *** **in function kata:partList/1... error undef". So it appears that there is an error somewhere in your calls.
The CW version is 20. I tried your solution on my computer with "Erlang/OTP 24 [erts-12.2.1] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:1] [jit]" and with this version your solution passes my tests.
There are not many CWarriors for Erlang. I tried the solutions that have already passed without problems.
Unfortunately I can't say more...

To post an issue give the input, your output, the expected. Otherwise it is impossible to correctly answer.

It has just been fixed.

There's already an issue opened about bad tests in C++ and Rust.

Thanks!

can also happen when you divide by zero

You can print it to std out.

SIGFPE 8 is a floating point exception. You should not use floating point numbers in this challenge at all.