Patch 4.3.4 was the final minor update to the "Hour of Twilight" cycle. It stabilized the game for the long term and includes all major Cataclysm features:
The Evolution of the World of Warcraft: Cataclysm Client 4.3.4 World of Warcraft: Cataclysm Wow Cataclysm Client 4.3 4 Download
: To connect to a specific server, locate the realmlist.wtf file (usually in Data/enUS/ or Data/enGB/ ). Open it with Notepad and replace the text with the address provided by your chosen server (e.g., set realmlist ://example.com ). Patch 4
Never use the official Battle.net application to launch a 4.3.4 client, as it will overwrite your legacy files with Cataclysm Classic. Never use the official Battle
That’s normal. The client will generate a new cache folder on first launch. If it doesn’t, manually create an empty folder named Cache in the root directory.
Don't forget to edit your Data/enUS/realmlist.wtf file.