hiya i've tried adding clips to 'project bin' such as mp4s, movs, avis, both small and large filesize and nothing opens.

Which version do you use? If you work under Linux please try with the current Kdenlive AppImage version 19.04.1c to see if there are any packaging issues https://files.kde.org/kdenlive/release/.
If the problem/issue doesn't occur when using the AppImage, then it's your configuration or packaging.

If you work under Windows: close and open Kdnelive a couple of times.