E200033: Another process is blocking the working copy database

If you are using Tortoise-SVN, sometimes it can go brain dead and the caching functionality gets stuck. Go into Task Manager and kill all instances of TortoiseSVN-Cache and try again.

Follow the below steps:

 $ cd /my/repository/.svn 
 $ mv wc.db wc.db.old 
 $ sqlite3 wc.db.old 
 sqlite> .backup main wc.db
 sqlite> .exit

Afterwards, do a svn cleanup. 

svn: database is locked, executing statement 'RELEASE s0'

Close all the files opened in the editors and run the clean up. It fixed the issue for me. I closed my Netbeans and executed the clean up command.