Usage question on the Cryptography plugin

I am having some issue using the sha1hashdocument function.  I can get a value with sha1hash(todocument(43763)) but is not the correct hash value.

What am I missing?

usage (where 43763 is the appian document id): 

  sha1hashdocument(todocument(43763))

getting the following error:

Expression evaluation error at function 'sha1hashdocument': The passed parameter(s) are of the wrong type. Received the type com.appiancorp.common.xml.JaxbConversionException: JAXB was not able to produce a value for typed value TypedValue[it=13,v=43763] as java class java.lang.Long.