ESS iView Errors?

I got this error for every ESS iView:

The initial exception that caused the request to fail, was:

java.lang.NullPointerException

at com.sap.pcuigp.tracking.BTrackingComp.isValuePackSystem(BTrackingComp.java:290)

at com.sap.pcuigp.tracking.BTrackingComp.onInit(BTrackingComp.java:206)

at com.sap.pcuigp.tracking.wdp.InternalBTrackingComp.onInit(InternalBTrackingComp.java:173)

at com.sap.pcuigp.tracking.BTrackingCompInterface.onInit(BTrackingCompInterface.java:115)

at com.sap.pcuigp.tracking.wdp.InternalBTrackingCompInterface.onInit(InternalBTrackingCompInterface.java:124)

... 71 more

Another strange information:

Web Dynpro Runtime Vendor: null, build ID: null, build date: Sun May 17 10:37:28 PDT 2009

How do I solve this problem? Thanks!