Steps to reproduce:
1. Use "Edit in MS Office" in Chrome or FireFox
2. The first time, a dialog from the browser appears asking to start MS Word. Check the option "Remember this decision" and click OK
3. MS Word starts. Close it
4. Click "Edit in MS Office" again
5. While MS Office is starting, you can see an error message. See error message behind Word splash dialog in screenshot.
In Chrome and FireFox, we are starting MS Office with a protocol handler (e.g. ms-word:xxx). There is no way to detect if such a protocol handler is registered or not. We are using a heuristic to detect if Office has been installed:
We are watching the focus in the browser. If the browser does not loose its focus with in 1 sec, we assume that Office has not been installed.
We loose the focus if this confirmation dialog is displayed. But if the user decides to "Always use...", the browser starts Word immediately. If Word is not yet running, it takes more than 1 sec until we loose the focus.
1. Remove this mechanism
Just try to start Office and do not track if we have been successful. The user has to figure it out on its own that MS Office has not started.
2. Extend timespan
We could extend the time we wait to loose the focus from 1 sec to something like 3 sec or 5 sec. This would make this more reliable, but still not bullet proof.