This is AltUI running on openluup. I have a few simple workflows that watch the status of switches: when switch is turned on it will be set to off after a few minutes. Working perfectly on all switches except for one (ID 10268).
When I turn on the switch the transition is not firing. When I reset the workflow, transition IS firing, workflow works as expected.
I turned on debug mode in AltUI, this is what I see in the log:
2017-11-25 09:08:48.745 luup.variable_set:5: 10268.urn:upnp-org:serviceId:SwitchPower1.Target was: 0 now: 1 #hooks:0
2017-11-25 09:08:48.745 luup.variable_set:5: 10268.urn:upnp-org:serviceId:SwitchPower1.Status was: 0 now: 1 #hooks:1
2017-11-25 09:08:49.023 openLuup.server:: GET /data_request?id=lr_ALTUI_Handler&command=oscommand&oscommand=tail%20-n%203000%20%20%2Fetc%2Fcmh-ludl%2Flogs%2FLuaUPnP.log&_=1511554849124 HTTP/1.1 tcp{client}: 0x50b428
2017-11-25 09:08:49.047 openLuup.server:: request completed (42480 bytes, 3 chunks, 23 ms) tcp{client}: 0x50b428
2017-11-25 09:08:49.047 luup.watch_callback:: 10268.urn:upnp-org:serviceId:SwitchPower1.Status function: 0x63cfb0
2017-11-25 09:08:49.060 openLuup.context_switch:: ERROR: [string "[3] I_ALTUI.xml"]:1218: attempt to index field '?' (a nil value)
2017-11-25 09:08:49.060 openLuup.scheduler:: 10268.urn:upnp-org:serviceId:SwitchPower1.Status ERROR [string "[3] I_ALTUI.xml"]:1218: attempt to index field '?' (a nil value) function: 0x63cfb0
2017-11-25 09:08:49.582 openLuup.server:: request completed (11898 bytes, 1 chunks, 5397 ms) tcp{client}: 0x8de388
2017-11-25 09:08:49.599 openLuup.server:: GET /data_request?id=user_data&output_format=json&DataVersion=108348574&_=1511554849125 HTTP/1.1 tcp{client}: 0x8de388
2017-11-25 09:08:50.799 openLuup.server:: request completed (1876571 bytes, 118 chunks, 1200 ms) tcp{client}: 0x8de388
2017-11-25 09:08:52.975 openLuup.server:: GET /data_request?id=lu_status2&output_format=json&DataVersion=108847895&Timeout=60&MinimumDelay=1500&_=1511554849126 HTTP/1.1 tcp{client}: 0x8de388