I have noticed that renshuu gives the (probably) wrong reading of 来れば when I checked some of the sentences in renshuu.
When the word is written with the kanji 来 (not with hiragana), renshuu gives the reading これば for 来れば.
However, in the conjugation table of the grammar page and in the dictionary, they both list the conditional form of 来る as くれば.
I have checked several dictionaries on the internet, and they all say that the reading of 来れば is くれば instead of これば. Microsoft IME doesn’t show 来れば in the choices dropdown when I type これば. The parser also doesn’t recognize これば as the conditional form of くる (when koreba is written in hiragana).
It also happens in the Japanese Lessons in Resources. The furigana of 来 contradicts the explanation, as Ichidan verbs simply replace the final る and do not change the pronunciation of the remaining letters.
So, I think this might be a mistake on the furigana system of renshuu, although it’s possible that I’m wrong and the reading given is actually valid.