When trying to set an external URL to a file in the Viewer I’m getting an Arg exception in .NET saying the name can be no longer than 260 characters.
We are sorry to hear that you have such issue. Unfortunately 260-char limit is an internal and inherent property of WinAPI and MS Windows at all, so the problem that you had described is not a bug but rather an inherited limitation (Why does the 260 character path length limit exist in Windows?). But we have good news for you - you can overpass this as described below.
You need to obtain a target document as a stream and pass this stream to the GroupDocs.Viewer. Please see an example:
.GetResponse().GetResponseStream(), “Grumpy-Cat-Colonel-Meow”, “jpg”, “Grumpy-Cat-Colonel-Meow.jpg”)
Please note that you need to specify a file name and extension in order to allow GroupDocs.Viewer to save this file in the “temp” subfolder properly.
If you will have more questions please feel free to contact us.