This is my scirpt file content:
apex export -applicationid 10001 -split -dir ..\apex -overwrite-files
This should export the application to the apex directory that can be found in the parent directory of the script file.
It worked fine in 25.2.2, and broke in 25.3.
In two commands it still works:
cd ..
apex export -applicationid 10001 -split -dir apex -overwrite-files