Something is wrong on graphics. I am getting purple and invisible graphics on a number of things. Some on NPC, some on items. Is there a way I can try to find out what the problem is and fix it? or should I reinstall everything over again?

thanks

You probably have corrupted shaders.
Download this:
http://www.tesnexus.com/downloads/file.php?id=20348

tried your suggestion but it did not help...

Here are somethings I am noticing:

-Fish out of water
-highway robber with pink/purple sleeves
-Some items pink/purple (swords, shoes and maybe those sleeves the highway robber was wearing)
-female orc partly invisible
-Partner 'Illi' goes invisible when in sneak position (standing his graphics are fine)
-Detail seems good but on some trees the trees are 'flat' with little detail, almost blurry

I really hate to have to start from scratch here, any suggestions greatly appreciated

thanks

have you tried reinstaling? it worked for me.

Spent so much time to get everything to this point. I would really hate to have to start all over.

How did you mess it up?

I was installed FCOM and some other mods. I thought it was working okay but as I said in the game the graphics are messed up. Some things are invisible, some are pink, some trees are details while others are not etc

Maybe there is no simple solution, with so many mods how can I know which one is causing this?

Use Form ID Finder or Refscope (search on Tesnexus) to figure out what mod is missing the textures/meshes...

For the fish out of water bug you are experiencing; if you're using MMM and the diverse waterlife addon there's an update that fixes it. Just find the MMM thread.

edit: btw it really helps if you post your load order so we can see if there are any problems with it.