ValueError: substring not found

[investlab]

I get an error telling: ValueError: substring not found
how can i fix this error?

[MonsterRoot]

replace string at line 96
text = text[text.index(']'):].replace("}","").replace("]","")
to this construction
text = text[text.index(']'):].replace("}","").replace("]","") if text.find(']') != -1 else text