Xtrafinder fails to work on Mac OS X El Capitan due to integrity protection | how to open folders in tabs

Two solutions to open folders in tabs:
1. disable the integrity protection:

1. Boot to Recovery OS by restarting your machine and holding down the Command and R keys at startup.
2. Launch Terminal from the Utilities menu.
3. Enter the following command: csrutil enable --without debug
Reboot your computer.

more : http://www.trankynam.com/xtrafinder/sip.html

2. Use Finder's tab feature:

Go to Finder:

Finder -> preferences --> check the box for "Open folders in tabs instead of new windows"

When you open a folder, please press command key and double click on the folder.