As explained in the title, most non-horriblesubs series will just not match when they are released and give an error as shown below.
I recently ran into a similar issue with YaRSS2-1.3.3.sp3-py2.7. Interestingly, the original YaRSS2-1.4.3-py2.7 was working perfectly fine. I have updated the Shana Project version of YaRSS2 to version 1.4.3 and made it available on my fork. I'll PR the changes if this fixes the problem.