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I am adding opportunity, when adding product to new opportunity its throw following error.

Attempt to de-reference a null object
Error is in expression '{!addSelectedProduct}' in page searchproduct
An unexpected error has occurred. Your development organization has been notified.

i have given read,edit access to opportunity, read access to product and price list.

thanks for your help

I am adding opportunity, when adding product to new opportunity its throw following error.

Attempt to de-reference a null object
Error is in expression '{!addSelectedProduct}' in page searchproduct
An unexpected error has occurred. Your development organization has been notified.

i have given read,edit access to opportunity, read access to product and price list.

thanks for your help