Last mission bug - can't get to hapiness island

[eXecutor-64-]

So. to keep it short,

Never had any problems on any other missions

but when I do the last mission (either out of comission or the one where you chase dimitri's heli) something strange happends

Have no trouble at the start, follow the black suv, kill all the goons, get on top of abandoned casino or whatever, Dimitri runs for his chopper, Pegarino jumps in his boat, I chase them, Jacob/roman come pick me up with a heli, i climb on it, follow Dimitri/Pegarino around and BAM

 

you know that scene where they crash on happiness island and you chase them on foot? NEVER HAPPENS

instead when the heli chase is over i get a view of Liberty city's builtings in the distance, the camera is fixed and cant move and i can hear i got a message on my phone (cant see the phone though) and thats it!

On some occasions, my screen becomes black and white (i think i am getting arrested but cant see niko or anything except the city buildings)

 

anyone heard of this one?

thanx

[CCPD]

1. Where did you get your game from?

Are you using any mods, cracks or trainers?

Do you have the latest version of the game?

Have you tried re-installing the game?

Have you manually removed games's installation folder (C:\Program Files (x86) OR C:\Program Files (x86)\Steam\steamapps\common\) before installing the game again?

Have you tried launching the game in different compatibility modes and/or as administrator (RMB click on games's .exe --> Properties --> Compatibility)?

Have you tried deleting your game's settings file (click here to see how)?

[eXecutor-64-]

So thanx for replying

 

well 1. got my game from a disc if thats what youre asking, non steam version

2. using only a couple of scripts, farnsworth's business, arrest warant, bank account, cautious drivers, deadly wrecks, fire patrol ,thats it no trainers

3. yes

4-5-6-7. no (and I am kind of hoping to do that as a last option) but since i have a feeling the answers above didnt solve anything i will get reinstaling as soon as i have time, and then report back

 

thanx again