Kitkat introduced quite a few security "enhancements" over previous releases. Many of them being local restrictions on what apps can and cannot access. Though it is was with good intentions, there is the issue of convenience.
Luckily though, it isn't a complete lock out. Apps now have to request an "access external media" permission (the list of things most people don't read when installing apps). Sadly, not all app developers have updated their software with this new permission for KitKat compatibility. So that is where you should be aiming your frustrations at.
If you have a rooted device, use a root privileged file manager, or if not, contact the developers of the apps that don't work, and request that they update them to be KitKat compatible.
I hope this helps! :-)