First thoughts that come to mind.... Have you tried adding the adwords api project to your solution as an existing project?
also try adding a reference to System.Xml or where ever that XmlSerializer in the exception lives. I remember having a simular problem once a while ago. Never really solved it. but managed to clear it by starting a new solution in VS and dragging the classes in to the project. Hardly Ideal - but like yourself I was at the end of the list of ideas. I hope it works out. I migrated without any major dramas -- =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~ Have you migrated to v200909 yet? The v13 sunset is on April 22, 2010. Also find us on our blog and discussion group: http://adwordsapi.blogspot.com http://groups.google.com/group/adwords-api =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~ You received this message because you are subscribed to the Google Groups "AdWords API Forum" group. To post to this group, send email to adwords-api@googlegroups.com To unsubscribe from this group, send email to adwords-api+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/adwords-api?hl=en