Symptoms
Under the languages with decimal_point separator different from ., e.g. , it is not possible to save custom cancelation fee, an error similar to below occurs:
Incorrect Cancellation Fee formula. Unexpected character ',' after '0' at position 1
Cause
The issue is caused by the bug with id #PBA-60685 ("Cancellation fee does not accept comma").
Workaround
Until the bug is resolved, to set custom cancellation fee login under english, where decimal_point separator is not modified.