You're asking us about some JSP code, but you haven't posted that code. Which makes it a bit difficult...
Anyway the error is saying "You asked me to evaluate the getReason() method on a String". You wouldn't get this error if you tried to evaluate it on a null reference, the JSP processor would just ignore that. So look at your code and find out why you attached ".reason" to a variable which is a
String and not a ViewHistDB object.