We've found a bug with Network Insight for ASA causing NPM to display no contexts or an incomplete list of contexts even when contexts are in use. You can still add each context and monitor them individually, but are unable to associate or link between them. This issue is due to a change in how ASA software version 9.2(4)22, and possibly others, displays serial numbers within the output of the "show module" command.
We're tracking this bug internally as NPM-9576 and have prepared a buddy drop to fix it. If you're running into this problem, please shoot me a PM or email and I'll get the buddy drop over to you. As we gather more information and verify our solution works in the field, we'll incorporate this fix into a regular release.
This fix has been incorporated into NPM 12.4.