We are having a problem with our add-in, which is a Word only task pane add-in with add-in commands. The add-in has passed the review and is published in the store. We can successfully sign up for a trial in the Office store and get the instructions on how to activate the add-in a document.
The add-in can be added to a document, at least to the point of showing the add-in command menu and button. However, when we try to start the add-in (as in opening it's task pane window by clicking the button in the Office ribbon) the add-in refuses to start due to not receiving the "et" parameter. We are at least two persons who can reproduce the symptom.
We have tested to add trials of another totaly unrelated add-in, which oddly enough does get the "et" parameter passed on and therefore works as expected. This problem really has us stumped; we have no clue what we can do to make Office actually send us the parameter?
Edit 2016-11-24: The add-in is ReadSpeaker Text to Speech for Office 365, can be found in Office store at https://store.office.com/en-us/app.aspx?assetid=WA104380516.
Also, by saying "not receiving the et parameter" above I mean that the actual parameter is indeed in the query string, but it is empty. So it looks like:
[...]/home.php?et=&_host_Info=[...]
This issue has been resolved (validation with "ReadSpeaker"). Please try it again.