If you want to use the SVNKit library for Subversion repository access,
please download an SVNKit standalone distribution from

www.svnkit.com

 and extracts its library, the .jar files,
into the subfolder

java/bin.api/lib

of this module. Make sure the jar files are in that folder rather
than in deeper subfolder that may have been created during the 
extraction. If present, the svn access module will pick up the SVNKit 
classes from there. 

Make sure the SVNKit licenses are appropriate to your use case!  

Please also check the how-tos on the z2 wiki in case you run into 
problems.