NoClassDefFoundError: R$layout after installing SDK and ADT updates

[Astha Sharma]

I update SDK to 22.0.1 and did related ADT updates. After updates my successfully running code has broken down with following error in finding xml resource-

unable to resolve static field 1108 (layout_name) in pkgname/R$layout
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some error log....
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java.lang.NoClassDefFoundError: pkgname.R$layout 

Please tell me what can be the reason of this error and how can I resolve it?