Adding a Certificate to Trusted Publishers using Microsoft Intune

I've been unsuccessful in getting this to work. I just keep getting a deployment error, and the certificate is not installed on my test device. I am unclear by what this means in your post above, "When using a certificate from an alternate source for any purpose, including those listed in this article, you need to add the root certificates for the PKI that issued the certificate to your managed Windows devices."

I added my code-signing certificate to the Trusted Root Certification Authorities store, but I am not sure that's what the above line means. Intune did successfully deploy the certificate in this case, but it will not deploy it to the Trusted Publishers store. 

I am also not sure I'm fully understanding the comment about removing line breaks. How do I verify that there are no line breaks or something wrong with my base64 formatting that might be interfering with a successful deployment of my cert?