dotless MVC nuget包不再工作了

I have dotless 1.3.1.0 nuget package installed on VS2012 and since 2 days or so it doesn't work anymore. Not even in older Projects that I didn't edit. Whole .less file stays colorless with no live sample on the right, no intellisense and it's not compiled into the .css file anymore. Already tried to reinstall it but that didn't help.I have dotless 1.3.1.0 nuget package installed