As a newcomer to NoLimits, and only having NoLimits 2 installed, I have found that some of the .nltrack and .nlpack coasters prepared for NoLimits 1 are missing some of the "teratextures" that were part of the standard NoLimits 1 install.
The freely available demo version of NoLimits 1 is available at the NoLimits Coaster development download site via http://www.nolimitscoaster.de/index.php?page=download#demo
Install that NoLimits 1 demo, and in it's installation folder copy the teratextures folder to the top level of the NoLimits2 installation folder. Then the missing textures is fixed.