The issue here is that, from the OpenMRS perspective you have logged in via the legacy UI (and therefore you have not chosen a session location) but you’re trying to view a page that comes from the newer reference application UI (which requires a session location).
Peeking at the code, there’s a bugfix for this specific error in the appui module, but it hasn’t been released yet. (But that just fixes the page header; it’s possible other things will fail subsequently if you have no session location set.)
This is the same problem that @sravanthi17 is running into at Appointment Scheduling is Broken On Openmrs Demo Instance. (Any chance you’re collaborating, and able to solve this together?)
Ideally you would log in from the Bahmni login screen (which requires a session location) rather than via the OpenMRS UI. (@sravanthi17 would that work?)
You can try building the latest version of the https://github.com/openmrs/openmrs-module-appui module from source, to see if this resolves the problem also.