.net - LINQ Design Time Errors Upgrading From VS2010 to VS2013 -

after upgrading visual studio 2013, seeing errors throughout 1 of wcf framework 4.0 projects. wherever there linq entity query seeing error upon using linq function such any(), single(), singleordefault(), orderby() etc:

 error  3   type arguments method  'system.linq.enumerable.orderby<tsource,tkey>(system.collections.generic.ienumerable<tsource>,  system.func<tsource,tkey>)' cannot inferred usage. try  specifying type arguments explicitly. 

example line of code generating error:

xxxxxxxxxxstatuslist = xxxxxxxxcontainer.xxxxxxxstatus.orderby(a => a.status).tolist(); 

as as:

 error  42  delegate  'system.func<businessaccess.entities.xxxportal.xxxxxxxxinfo, int,  bool>' not take 1 arguments 

with example:

xxxxxxinfo = xxxxxxxxcontainer.xxxxxlist.where(c => c.xxxxxxid.equals(xxxxxxid)).single(); 

here have tried:

• building project. builds , hides errors temporarily until code edited.
• removing linq reference , re-adding. unsuccessful.
• checking target framework still 4.0. is.
• checked migration log 2010 2013, showed successful migration.
• upgrading vs2013 update 1: in progress right now...

any ideas appreciated. it's referencing/compile configuration issue, it's eluding me.

many time.

we found internally. else seeing blanket problems intellisense, yet able build successfully:

• visual studio 2013 not compatible mvc3, causing of errors in our ui projects.
• also incompatibilities entity framework 4 occurring, seeing above.

i hope helps out somewhere.