Unity5.5 Missing Toon Shader ?

Hello there,

Opened a project I built in Unity 5.4.3 in 5.5 and I'm missing my Toon Basic Outline shaders I used on a Mixamo 3D rigged model. I went to re-import using the Assets/Import Package/Effects fix, but it won't let me select the shaders (perhaps because they're already seemingly in the project?).

Unfortunately I'm having issues now re-opening the project in 5.4.3 (assets have disappeared) so I'd like to try and fix this problem in 5.5

I don't want to delete what I currently have because of animations/scripts attached. Would rather just fix the shader.

Thanks!