Hello,

Sorry about that... First of all let's make Oxygen start again. The 
first step is to identify Oxygen's options directory. Depending on the 
platform the options folder is located as follows:
- Windows XP - [user-home-folder]\Application Data\com.oxygenxml
- Windows Vista/7 - [user-home-folder]\AppData\Roaming\com.oxygenxml
- Mac OS X - [user-home-folder]/Library/Preferences/com.oxygenxml
- Mac OS X - ~/Library/Preferences/com.oxygenxml
- Linux - [user-home-folder]/.com.oxygenxml

Inside this directory search for and remove the directory: 
git.support-1.0.7

Oxygen should now start again.

Do you have, by any chance, any other plugins installed inside Oxygen? 
One of these plugins might be contributing a slf4j jar inside the main 
Oxygen ClassLoader. To find out which plugins are installed, please go 
to Options->Preferences... on the Plugins page. Nevertheless, we should 
take care of such situations so I will let you know as soon as we 
release a fix.

Best regards,
Alex