I have a meeting tomorrow to discuss concerns about the many bugs inside of an application I recently upgraded.
How do I prepare for such a meeting?
Try to front-foot the conversation and prepare:
If I was attending a meeting I would want to be well prepared and not caught like a deer in the headlights. Good luck!
While doing your own prep in terms of issues and potential solutions is important, you should also prepare for the emotional element.
Often in this kind of meeting the client wants to be heard as much as anything else. Mentally prepare to let the affected parties vent without taking anything personally or becoming defensive. Be ready to respond in the affirmative to the various points in a neutral way, with a words like 'understood', 'okay', 'uh-huh', 'I'll make a note of that', etc.
After they have expressed initial concerns, ask if there is anything else. Continue asking that question and responding calmly/neutrally until until they run out of things to say.
After that initial venting session, you should be able to move the discussion on to next steps in a productive way, focussing on prioritization and solutions for moving forward.
I find it helpful to remember (and sometimes mention) that from NASA to Microsoft to Apple, nobody is shipping bug free code. Bugs happen, this is normal, it's the next steps that matter.
What you say is a bit unclear. If you installed a new version of your company’s software at a customer site, and the customer is unhappy with the many bugs in the new version, then the most important thing for you to do is that you agree with the right people at your company what you can say to make the customer happier than they are right now.