Online targets throwing "Object reference not set..."

[lorynj]

In my main project, I've noticed that all my online targets are throwing "Object references not set to an instance of an object" when I attempt to make changes.

For example, when I attempt to change skin

MadCap_Flare_2018_Set_Skin_Failed.png

And when I attempt to change the advanced option "Synchronize navigation elements with TOC entries"

MadCap_Flare_2018_Error_Top_Nav_Path.png

After making any of these changes, when I reopen the online target, the "change" has not taken, and the previous setting is in force. Any idea what might be preventing me from making changes to the online targets?

[lorynj]

Well, somewhat disconcertingly, a reboot was all that was needed to fix this. Bit of a mystery as to what might have caused the issue though.