To many animation extension in ytyp or ymap files.
like this
<extensions>
<Item type="CExtensionDefLightEffect">
or
<extensions>
<Item type="CExtensionDefParticleEffect">
the game have a max what you can load in the same time.
so if you have <extensions> in ymap files unload the files in a small range.
if you have <extensions> in ytyp files load the ytyp only if player in range.