OSB Error : Failed to set the value of context variable "body"

A common error one can get while assigning variables in OSB is  -

Failed to set the value of context variable "body". Value must be an instance of {http://schemas.xmlsoap.org/soap/envelope/}Body.

OSB has some predefined variables like body and it expects that the variable body content should always be enclosed with <soap-env:body>. Inside this element you can assign any value.

If you don't want to be worried about this every time manipulating body variable then you must use "Replace" instead of "Assign". Just select "Replace node contents" and replace will take care of not removing the <soap-env:body> from the variable.