I have recently experienced that Lync stopped joining Online Meeting without pressing F5, after IE9 installation.
I asked some colleagues and searched the net for solution, but no really good answers.
After some investigation, I discovered that this must have something to do with the MeetingJoinHelper ActiveX component.
The first thing to verify is, that the ActiveX component is properly configured, to to this:
- Open Internet Explorer.
- Press the Alt key to bring up the Internet Explorer menu bar.
- Click Tools | Internet Options.
- Once the Internet Options screen appears, click the Programs tab.
- Click Manage add-ons.
- Click the Currently loaded add-ons drop-down near the left-hand side and select All add-ons.
- Once all the add-ons appear, locate MeetingJoinHelper Class. The MeetingJoinHelper Class add-on enables the MeetingJoinAxOC.dll ActiveX Control to launch the Lync client.
- Verify that the status is Enabled.
- Right Click the addon, and select More Information.
Click Remove all sites, and Allow on all sites.
This will “reset” the ActiveX component, and the addon start to behave like it is supposed to.
I hope that this solves the issues you are experiencing – It sure did the work for me!