I'm going to be lazy today and make you solve the problem.

Did a recent security hotfix change change the way we handle UNC paths with spaces? Normally, if we open the Run dialog and type \\server\share\Support Library\, the Support Library folder opens. But recently it stopped working. Instead of opening the Support Library folder, we get the Open With dialog:

Open with

Choose the program you want to use to open this file:

File: Support

♔   Contoso Chess Challenger 5.0
♫   Contoso Music Studio
◕   Fabrikam Chart 2.0
ℒ   Litware 2010
$   Woodgrove Bank Online
 
 
 
 
 
 
 
☃   Happy Holidays!
 
 
 
 
 
  Always use the selected program to open this kind of file

 

Can you figure out what happened recently that introduced this problem? You have all the information you need.