Formula working and then changing to #no match error

Angie Little

Has anyone had a working formula somehow change to #no match? I've had several instances where the formula is working and then for some reason changes to give me a #no match error.

Jake Gustafson

Is there a data discrepancy that is causing the error message? May want to add in an IFERROR function to handle those differently. My first guess would be a slight data variation (i.e., extra space at the end or a lower-case L instead of an upper case i).