How to exclude a folder that is producing warnings/errors in an Eclipse project?

I encountered a similar problem and resolved it by moving the folder into my project folder. I then went to:

1. Project > Properties > Resource > Resource Filters > Add...
2. Set Filter type = Exclude all.
3. Set Applies to = Folders.
4. Set File and Folder Attributes = { Name, matches, < your_folder_name > }

You can use the Configure Contents... on the menu of Problems panel. There you can create a new configuration and set the scope to On Working Set:. Click on Select... and create a new working set that excludes the folders you don't want.