Excel button on Customer List greyed out

Hello,

I'm stumped on this one. In Customer Inquiry>Customer List lookup there is an Excel export option to the left of the printer icon. For this user it is greyed out, but for me it's working fine. I looked into Role Maintenance for the user's roles and I don't see a setting that looks like it would enable this, and she's been able to do it for years. 

Any ideas?