When a request that contains Path Info is sent to the server (e.g. /myitem.aspx/somepathinfo), Sitecore may throw the following error or resolve the context item incorrectly.
[ArgumentOutOfRangeException: Length cannot be less than zero.
Parameter name: length]
System.String.InternalSubStringWithChecks(Int32 startIndex, Int32 length, Boolean fAlwaysCopy) +10084024
Sitecore.Web.RequestUrl.get_ItemPath() +98
Sitecore.Pipelines.HttpRequest.SiteResolver.UpdatePaths(HttpRequestArgs args, SiteContext site) +141
Sitecore.Pipelines.HttpRequest.SiteResolver.Process(HttpRequestArgs args) +64
...
To resolve the issue, download and install the following patch: Sitecore.Support.311387.zip