The Problem In This Details As I Did:

    *Installed Mack Mega Coaster Addon
   *Installed both Europa Addon 1 & 2


After I both installed both PEP-Team Addons[EUROPA PARK ADDON 1&2] for the Mack Mega Coaster I just downloaded, when I opened up RCT3 to just test the CTR, it shows this: 

"CTR_MackTrackML04: track section 0 (0 based) of 3799 unresolved: see trr file"

I installed everything in the right way. NEED HELP ASAP

Hey! Welcome back! And, I can't help you, I am not a RCT3 player. But, have bo fear, there's SO many RCT3's here. Just ask em.'

Hi and welcome back. Wish I could help with your situation but I'm not sure so hopefully someone else may be able to help. Perhaps doing a search on YouTube may be useful to. It'w worth a try.

I was hoping someone could help you by now :/ I have absolutely no experience with any of the Pep team's stuff unfortunately.... From the looks of it there is a piece on your Mack coaster CTR that either cannot load, or when it is used will crash the game. My only suggestion is to perhaps use the CTR editor to try smoothing the error out, but alas, I have no experience with that either :/

Alright. So the process that I used was really complicated. Since the original PEP wasn't for the mack coaster (I believe it was for the family coaster), you have to use the CTR creator to put the Mack car onto the track. Silvarret is much mored qualified to talk about the CTR creator than I am so watch his video here: https://www.youtube.com/watch?v=NBGhDVHjQ6s

The other and easier option is to use the default RCT3 extended track or the blitz track. Although you don't get the precision of the ML04 track, it's good if you just like the Mack Mega-coaster car. Use the CTR from this link:
http://www.shyguysworld.com/index.php?topic=11039.570

hope this works for you.