For more details see https://groups.google.com/forum/?fromgroups#!topic/symbolsource/wC2_h9rWD6E.   I assume this is a nuget.exe and //symbolsource.org/ repository related issue but am posting here just in case anyone on the nuget side of things is aware of what could be causing this.

status update

The fix for this is now live on //symbolsource.org/ see https://groups.google.com/forum/?fromgroups#!topic/symbolsource/wC2_h9rWD6E for details.