My data looks like this:
Why is this error showing up?
This is a common result of imprecise matching, such as with whitespace problems.
For example, if you imagine that the grey shading used in codeblocks on StackExchange represents the whitespaces in your Excel cells, then
AK
is technically the same as
AK
You can trim and/or use wildcard chars to allow matching to skip spaces. For example:
=VLOOKUP(CONCATENATE("*",TRIM(A2),"*"), $E$2:$F$5, 2,FALSE)