Mod Issues

[gpower7 0]

I downloaded several mods a few were successful and I've been using them regularly but all landmark mods have a giant giftbox over them when I try to place them. 

[matias93 7,535]

That box means you haven't installed all the dependencies (needed files) to use that landmark lot. Check the post from where you downloaded the landmark and search for its dependencies requisites; browse this site exchange (or google) for the needed files, download and install it (with the game closed, of course); you should see no more brown boxes. If the issue persists, ask here again

[A Nonny Moose 8,261]

Also, make sure you have the Maxis default plugins named BldgProps_Vol1, BldgProps_Vol2.  Items from these files may be included in some plugins without being mentioned as they have been around almost since the beginning and authors may use them without knowing that they are separate.