No devices detected. – Form Viewer Review

Form version 1.1.0 (4) (OS X) Yosemite 10.10.1 (14B25) iOS 8.1.2 (12B440) Same Wi-Fi network. This is a Time Capsule router. Double-checked the firewall settings, Form is in the "allowed" list. It used to work with my old iPhone 4S. But now, 'No devices detected'. Tested with an iPad 2. Same issue. How to debug this issue? Thanks.
Review by singledev on Form Viewer.