No textures when exporting to Collada (2.5 Alpha)

Could someone please help me with this problem? I’ve Googled and searched everywhere for an answer and can’t fine one!

When I export a simple cube in Collada, the textures don’t export; only the mesh. When I look at the console, I get this message:

RNA_string_set: WM_OT_collada_export.filename not found.
RNA_string_set: not found