I checked out the fix for L2Walker 2.13 using l2.net, and found this to be much easier.
Step 1:
Add these to HOSTS file :
127.0.0.1 l2authd.lineage2.com
127.0.0.1 l2testauthd.lineage2.com
192.168.1.12 nprotect.lineage2.com
Step 2:
1. Right Click My Computer -> Click properties -> Go to the Device Manager
When The Device Manager Opens Right Click on The Name of Your Pc and Click "Add Legacy Hardware".
2. Click Next and then Click add Hardware Manually -> choose Network Adapters -> Then choose Microsoft as the Manufacturer and then On the Right Side Choose "Microsoft Loop back adapter".
3. Edit tcp/ip properties on loopback adapter to 192.168.1.12 with a subnet of 255.255.255.0
Step 3:
Download TCPTUNNEL and run the "forward.bat" then start l2walker.
Congratz, you are now ready to bot freely!