I am trying to log in to the Manager App in Tomcat 7.0.22 for Mac OS X 10.7. Here is the error I am getting: http://f.cl.ly/items/421q1K3f1i0X1H1M181v/so.tiff
I had same error then I changed password in users.xml. It solved. If you use some special chars like & or @. It doesn't work. Remove it.
&
@