Questions & Answers about אם יש טעות בעותק ששלחת, אני אסרוק את המסמך שוב.
יש means there is / there are. So אם יש טעות literally means if there is a mistake.
This is a very common Hebrew structure for existence or presence. Hebrew does not normally use a present-tense form of to be the way English does, so יש is the normal word here.
Because the sentence means:
If there is a mistake now / if it turns out that there is a mistake, I will scan the document again.
Hebrew, like English, often uses a present-tense condition with a future result. The idea is that the condition is being checked now, and the action will happen afterward.
If you said אם תהיה טעות, that would shift the meaning toward if there will be a mistake, which is a bit different.