Hi, I found most of our pc has missing store.sdf suddenly, and before the missing events, their upper folder's PolicyPlatformClient.log is still updating. What is the cause of this problem, what to do with that file, how to fix them massively ? Is that any way I can check out how many users in my network are having this problem via sccm?

What does ccmeval*.log on the client? It should detect that there are issues with it.