The reality of customer experience issues

I recently launched a new feature on one of our business systems and the target end-user was seemingly very happy. Shortly thereafter I received a note:

In the new tool that you programmed for [company], is this still working?

When I put in a Member ID in the open box, it no longer shows any info:



Any advice? Did something change?

Hmmm.

I told him no... (yes, the pixelized area is where he put the MemberID).