I was looking again at a question related to installation problems posted yesterday. I had some feedback with the OP trying to find the problem and the OP finally solved the issue. Today I checked again the question and all comments were gone. Since I could probably have the same issue, I'm interested on how to detect the issue.

What are the criteria to delete comments? In this case, I didn't delete mine, so somebody else did it (for both I suppose, OP and I)