Bullhorn Integration>Regression>"Object reference.." error while assigning tours

Today's date - 11 Aug 2017
Employment Start Date - 15 Aug 2017

1] Access bullhorn tour details page.
2] In drop down all tours are displaying:

Eligible from System (PB2, OB2)
Not System eligible. (PB1, OB1)

Steps:
Try to assign OB1.

Issue 1]
While trying to assign OB1, (which is onboard tour and should available to employee after employment), while assigning this tour, PB2 which is system eligible is get assigned.

Expected:
Either show only Preboarding tours only in the drop down as employment start date is future date. Also same tour get assigned after assignment.

Issue 2]
Object reference error is displaying while assigning any of the remaining tour.

Refer attached screenshot for more details.
Cc: Prasad Pise, Saurabh Sablaka