In the json settings you posted above in this thread you have the port set to 80 (onvif port is different to port which is what will be used for the snapshot) you need to make this match the port for the snapshot. If it is static and not changing then that should work for now till I fix the bug.
You can ignore some log errors if they only occur when your ripping out and replacing a binding when it is still running.
The communication error is correct, you need to check the port setting is correct and if it is on 80 and the camera needs another number, you need to change this. The bug when fixed should allow it to pick up the snapshot is on a different port.
EDIT: I checked and if you supply the snapshotUri in the things settings you should be able to work around this and not use ffmpeg and have working snapshots. A manually supplied url seems to be handled correctly with no bugs from a quick glance.
Great that is a work around and will use more CPU, but will get you working and hopefully you can use PTZ and have working onvif motion alarms and the like.
Cool it is working from the sounds of it, just need to see if you can move the camera using the other widget here
It is very common for cameras to not support all the methods to move a camera, so please take the time to test them out in the onvif device manager program. ABSOLUTE/RELATIVE/PRESET etc…