Problem importing and/or exporting the collada file format

Just started to learn DirectX 11 after a long break from 3D programming (previously used Directx 9). As .x is no longer is supported I decided to use .dae (collada) as it’s the default format in Blender. To convert my old .x files to collada I used Open Asset Import Library (assimp).

When I imported the model to Blender it was REALLY small and had roguh edges. As I have very little experience with 3D graphic programs I decided to export to the same file format (collada) and see if anything had changed. I opened the file in assimp viewer and the result was not pretty. The model had really rough edges, didn’t have any textures, the bones (frames) was all messed up and the meshes in the model was no longer attached to each other.

There was no errors importing/exporting the model and I didn’t make any changes to it in Blender. If I open the converted collada file (.x -> .dae) in assimp everything looks fine. So I don’t think that there are any problems with the conversion from .x to .dae.

Is there something I need to do before exporting (or importing) from blender?