My guess is that you are using "pseudo=read" in addition to "gen" in the route section but not providing a pseudopotential after your "gen" section. Normally the input would be:

(in your route)

#p m062x/gen pseudo=read {...etc...}

exampleName

0 1

{geom}

{your gen section}

C O N H 0

6-31+G*

****

Cu 0

lanl2dz

****

{pseudopotential}

Cu 0

lanl2dz

****

${NBO section}

You can try to add the pseudopotential section for your Br, in this case, and see if that fixes the issue. I've added blank lines, above, as well as block descriptions which should be omitted.