I want to know does all the mods installed before on default skin will work properly with new installed skin or need to edit again new skin templates files Forum software is VBulletin
Some of them work, some not! Because some requires the theme edit, and you must have edited the default skin, so you need to apply the changes to the new skin too!
The best bet is to install new skin and check it out before you go live with it. Like Al-Mujahid said many products make template changes when installed and these need to be changed on your new skin as well. Mark
If it's something complicated, you'll be out of luck. If it's one of the more older simpler ones they'll give you more success.
The best way to know it is to check if those mods are compatible on your vbulletin version and your template too! I've been using vbulletin for a long time and by the way if you know what you are doing (like installing mods, modifying etc..) you shouldn't be afraid to try it out.
Depending on the mod. If the mod required you to do a template change, then yes you will have to update it again on the new skin. But there are some mods that don't require any template changes meaning you don't have to do anything