Microsoft Office 2011 no longer working with Yosemite 10.10.2

Two things you can try :

1) Make sure you have the latest updates installed. Office 2011 has been updated since release, so it pays to ensure the latest versions of all applications are installed.

2) Perform a Repair Permission on your Macs hard disk. This has been known to cure slowdowns in a a few Applications including Office 2011. Repair Permissions is a feature of Disk Utility found in the Utility folder in Applications.

If the problem is that some characters do not appear but small rectangles are shown instead, as I suspect, then it’s probably a font problem. Quite possibly the Windows machines lack fonts that contain the characters needed.

In that case, you could download and install some suitable free fonts on the Windows machines. To identify a character (possibly displayed as a small rectangle) in a Windows version of Word, click on the position right after the character and press Alt X. This turns the character to its Unicode number. For example, ∅ turns to 2300. The Unicode number can then be used at http://www.fileformat.info/info/unicode/char/search.htm where you can find information on font support to different characters, using e.g. character name or Unicode number as key.