I would say a more appropriate word for repair in your context is reficio, rather than emendo. For what I can see in L&S, the latter seem to be used more abstractly, or for non-physical things. Conversely, reficio seem to refer to physical things, including examples like walls, gates, weapons, and so on. L&S also gives it the translation "repair", which emendo does not have. Another option could be resarcio, which is used with clothes, and can be translated as "to patch", which is perhaps more analog to what a software update is.
So, for reficio, the conjugation in your example would be refecimus. For resarcio, it would be resarsimus.
Finally, "You are welcome" is an expression, so translation is more complex. There is already a dedicated post on this site about it, suggesting there is not a native equivalent, but nihil est might be a decent modern compromise. Now, nihil est means "it is nothing". So in the context of a finished past action (it was fixed and the problem is no more, hopefully), it is better to use the perfect tense: Nihil fuit.