We are not sure why Internet Explorer does not display the error. Are you displaying the same folder in both browsers? I also noticed that for some reason the address bar in the file explorer has two slashes between the folders - App_Data//Documents//. Perhaps Internet Explorer manages to work with two slashes but Firefox cannot? If you are using a custom content provider, check how you are generating the path of DirectoryItem objects and ensure that there is only one path separator.
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