**Steps to replicate the issue** (include links if applicable):
* go to https://www.wikifunctions.org/view/en/Z24322, and fully expand the result validation to see that the second parameter of the number it is comparing to is "" (it should have been "3"). This is an invalid natural number to compare to.
* go to https://www.wikifunctions.org/view/en/Z13708 and note the status of all the tests/implementations. All are "running".
**Similar behavior observed**
* https://www.wikifunctions.org/wiki/Z19509
**What happens?**:
* All the tests/implementations are indefinitely marked as "running" at https://www.wikifunctions.org/view/en/Z13708:
{F59548920}
* The error created as a response is so big that the API fails with "This result was truncated because it would otherwise be larger than the limit of 12,582,912 bytes." ([[ https://www.wikifunctions.org/w/api.php?action=wikilambda_perform_test&format=json&wikilambda_perform_test_zfunction=Z13708&wikilambda_perform_test_zimplementations=Z16248%7CZ18128%7CZ13709&wikilambda_perform_test_ztesters=Z24322&uselang=en | see api call ]])
**What should have happened instead?**:
* It's understandable that the broken test itself fails or exhibits strange behaviour. But this should not affect the outcome of all the others, especially if it's not connected.
* UI should replace "Running" with "Failed" after the response is received