I made my really good terrain, but it requires too much nexus (whatever that is). How do I make my terrain work. It appears non-existent when I run the level through SED test.

It requires too much nexus? Did you try to increase the nexus?

WED >> File Menue >> Map properties

Here you can adjust the nexus. I think it´s something like the reserved memory and it tends to grow with your ambitions ...

Didn't work. Says:

Error E1201
Nexus too small (1835012)

What's your current nexus size? How much did you increase the nexus to? Provide more information if you want help solving your problem.

Since the error message is "nexus too small", I think you can conclude that your nexus size is not set large enough. The max you should ever really set it to is 200, so try this and see if it runs. If so, then press F11 and look at the number next to the word "nex" to see how much of the nexus is being used.

You will probably need to decrease the detail of your terrain if it alone is causing the nexus to be not large enough.

I set it to 200. The nexus is running at 107000 or something close to it. But the terrain doesn't load, so I think it maxes out the nexus.

Does it still give you that same error message, or does the terrain simply not show up?

When I test run it through SED, it said level1.hmp not found. When I run it through level1.wmb, it gives me that error message.

I think it´s like this.
Your level with the terrain would require more than 1,8 GB Nexus (preallocated virtual memory). This is indeed too much. I´ve read somewhere it´s impossible or becomes a source of instability to increase the Nexus beyond 1024 MB.
Most PC´s couldn´t handle even this, so the recommendation would be 200 MB.
If you´re target customer has a high end PC, you can go higher.

Nevertheless you can create big levels with terrain, if you split your large terrain into smaller cells, which are loaded (and removed) dynamically at runtime, depending on the visibility. It´s a little bit tricky, but I just recently explained this to another user, and it might be interesting for you. The thread is something like "huge levels with terrain" in the modelling section ...

Splitting the terrain into smaller cells is automatically done by the engine, and must not be done by the user. So better forget that advice.

If your terrain is not found, increasing your nexus won't help. Better check whether the terrain hmp file exists and is in the right folder.