Well, if you don´t have a textured view, you should make sure, that everything (including directX) is properly installed.
A 6.5 uses the DirectX9.0c version of April 2006. Maybe you need a Windows Update.

If you open WED >> File >> Preferences you could look which GXL is currently used. It should be GXL2BASDX9.DLL. This works at least for me.
There is this d3dx9_30.dll which should be in your Gamestudio folder and maybe also in the Windows System 32 folder.

If all of this doesn´t help, you can also try to reinstall GS or ask Conitec.