Lync 2013 Meeting Icon Missing

Recently a client had an issue with the meeting icon not appearing in the Lync client. Initially I though this was an Exchange EWS integration issue, however upon further investigation found that all other EWS functions were working as expected. I had never come across this issue before so I took to the internet to see if anyone else had seen this..... Once again Ken Lasko to the rescue :)

It appears that the July 2013 (CU4) client update for Lync introduced some new icons (Q&A and Meeting), however the files that contain those icons were not updated as part of the same process. Rather stupidly these files are updated separately by Office updates. Moral of the story - If you see this issue make sure that your Office updates are up-to-date.

In summary:

• MSO.DLL and MSORES.DLL contain the icons used by Lync, however these don't appear to be updated by Lync specific updates even though Lync relies on them
• To ensure MSO.DLL and MSORES.DLL are updated to support the new Lync icons, make sure Office is updated at the same time. Look out for KB2817489 and KB2817491 (they appear to be the same update)
• Compare the versions of these files before and after updates and make sure that they change. In Office 2013 x32 installations, those DLLs are found in C:\Program Files (x86)\Common Files\microsoft shared\OFFICE15