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What is the preferred/best location for app-generated log files for packaged apps? The user's AppData/Local folder for the app? Or somewhere else?
There is no best location. It depends on your requirement where you place the log file. You could put the file wherever your app has permission. If you are developing a UWP app, you could check this document- File access permissions about the file permission that UWP apps have and choose a place that is suitable for your requirement.
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