Okay so like the title and description said, I tried downloaded two things:
A scythe,
And the pokeball mods,

I get them theyre working and everything, but one problem..

They appear as gigantic yellow squares with blue explination marks in the middle!

Can anyone help me fix this problem??
Or explain why it is happening?

Incorrect installation, the meshes and texture files are missing at the correct locations.
If you are new to mod installing the better is reading tutorials about it. You will find one pinned at this forum.

If you are already acquainted with the /data structure so you will need to read the mod(s) documentation and verify where those files or folders must go. If this is not the problem, so the mod may be incomplete or have flaws and in this case there is a high chance this being a repeated complaint at the mod commentaries and rating.

Long story short: download Oblivion Mod Manager. With little effort on your part, OBMM can take the archive your mod came zipped in, put all of the stuff where it needs to go, and make it so to activate the mod, you simply select it from a list and hit "Activate". Easy as that.

OBMM is definitely the best way to package a mod. I use it a lot, and it never misses.

Without using OBMM

Except for the very simplest mods, a mod will be split up into several parts. the .esp which is the actual mod, a Texture folder, a mesh folder and possibly others. All need to be in the proper place for the game to find them.

Yellow blocks indicate that your Textures are not in the right place.

The .esp file goes into the oblivion\data folder. It appears that you have that.

Textures are usually packaged in a subfolder named 'textures'' in you zipped folder. These should be placed in the Oblivion\data\textures folder. Either copy or move them there from where your unzip program placed them. Usually you can find misplaced textures and mesh files in a folder in the \data folder with the name of your mod.

example you are installing XYZ mod. when you unzip, it shows four files. XYZ.esp - this is the mod - it should go into the Oblivion\data folder.
xyz readme.txt this is the information that you need to read before installing, as it may have more info on special install instructions or problems for this mod.
With most unzip programs, just extracting all to the Oblivion \Data folder will place the meshes and textures into the proper folders automatically. If it asks if you want to overwrite answer yes. If you answer no, the meshes and textures will not be installed. and you will see the yellow blocks. If you did this, reinstall and answer yes.

If the unzip program doesn't put them in the right place, I recommend using 7-zip a free unzipping program available on tesnexus, here: [url="http://tesnexus.com/downloads/file.php?id=15579"]

Some unziping programs will make a new folder in the Oblivion\data folder with the name of your mod (in the example, XYZ) You will find the textures and meshes in it. Move the texture folder from the XYZ folder to the Oblivion\data\textures folder, again answer yes when it asks if you want to overwrite.

Do the same with the mesh folder.

Hope this helps.

Sorry to correct you, but yellow exclamation blocks are missing meshes.

Thank you Herosinger. I stand corrected. The yellow blobs are missing meshes. Missing textures show as purple. But the cause is the same, something not properly downloaded. The procedure I outlined will correct either, or both.

Indeed. It's usually best, Feydster, to check the archives before you extract them in order to make sure they are arranged correctly.

I download the oblivion mod manager and i cant add the mesh file. i almost threw the the computer across the room trying to add it. please reply as fast as possible before i fling it across the room.

Give me a link to the two mods you downloaded. I'd like to get them and try to make them work in my game. Sometimes, the correct path is not stored in the zip and meshes get dropped where ever they land. I've had this issue with other mods (including one of mine). It's an easy fix if you know what to look for.

thanks here it is http://www.tesnexus.com/downloads/file.php?id=14174 pokeballs, mod manager is http://www.tesnexus.com/downloads/file.php?id=2097 thanks a lot.