In this guide you will learn how to fix an intentional microsoft bug that ruined sounds for earlier versions of minecraft, to try to force users to use their updated vanilla versions instead… This fix is quite easy however.
Go to this link and download the replacement resources folder. Basically we just need to overwrite the current resources folder with the new sounds so they work in older minecraft versions.
Next you will need to extract this file:
Right click on the file and hit extract all. Rename the extracted file to “resources” without the quotes.
Next hit your Windows Key and type in %appdata% and hit enter. This will take you to your roaming appdata folder. Inside here you need to find the .technic\modpacks\hexxit folder as shown below in the following two images.
Copy your new resources folder and paste it inside this spot exactly to overwrite any previous resources folder. After this is complete you will need to reboot your game. All in game sounds should now work properly!