They'll catch the errors eventually.

When we bought this place we had a first mortgage and a higher interest 2nd mortgage and 10% down (80/10/10 - to not have to pay for PMI). Of course, there were about 6 copies of each mortgage that we had to sign.

About a year after we moved in, we got a letter with one of the 2nd mortgage sets that needed to be signed. We signed it, no issues.

(We paid off the 2nd mortgage quickly and eventually refinanced the first at a lower rate, and ended up paying everything off in less than 20 years by paying more in principal each month. I have no idea how people can do things like that these days, and it probably doesn't make sense to do so with less than 3% rates now...)

Good luck!

Cheers,
Scott.