Why do I get an error in Firefox when uploading an image to the sitecore media library?

Question

Every time I try to upload an image to the Media Library using Firefox, I get a pop up error that says "An error occured while uploading a file". Upon examination of the sitecore logs, I see the following in the stacktrace:

288 11:29:27 ERROR Application error.
Exception: System.ArgumentException
Message: Illegal characters in path.
Source: mscorlib
at System.Security.Permissions.FileIOPermission.HasIllegalCharacters(String[] str)
at System.Security.Permissions.FileIOPermission.AddPathList(FileIOPermissionAccess access,        AccessControlActions control, String[] pathListOrig, Boolean checkForDuplicates, Boolean    needFullPath, Boolean copyPathList)
at System.Security.Permissions.FileIOPermission.AddPathList(FileIOPermissionAccess access,     String[] pathListOrig, Boolean checkForDuplicates, Boolean needFullPath, Boolean copyPathList)
at System.Security.Permissions.FileIOPermission..ctor(FileIOPermissionAccess access, String[]   pathList, Boolean checkForDuplicates, Boolean needFullPath)
at System.IO.File.GetLastWriteTimeUtc(String path)
at Sitecore.Resources.Media.MediaData.get_MediaId()
at Sitecore.Resources.Media.MediaCache.CanCache(Media media, MediaOptions options)
at Sitecore.Resources.Media.MediaCache.GetStream(Media media, MediaOptions options)
at Sitecore.Resources.Media.Media.GetStream(MediaOptions options)
at Sitecore.Resources.Media.MediaRequestHandler.DoProcessRequest(HttpContext context,   MediaRequest request, Media media)
at Sitecore.Resources.Media.MediaRequestHandler.DoProcessRequest(HttpContext context)
at Sitecore.Resources.Media.MediaRequestHandler.ProcessRequest(HttpContext context)
at     System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute    ()
at     System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute    ()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

Heartbeat 11:30:04 WARN Memory usage exceeded the MemoryMonitor threshold.
Heartbeat 11:30:04 WARN Memory usage: 1,680,764,928
Heartbeat 11:30:04 WARN Number of suppressed logs due to the minimum time between log entries: 10

I can tell there is some kind of illegal character exception, but I don't know where to look from here. What could be the cause of this issue and how might I fix it? Is there somewhere to configure the file path in sitecore?

I am using Sitecore 6.5

Answer 1

I had this problem also on Firefox and Safari. Please change setting Upload.Classic to true. It will be :

 <setting name="Upload.Classic" value="true" />