I assume there is a version mismatch between what Ultralibrarian delivers, and the KiCad version you are using. A quick way to fix it for you is to create a footprint file with an NPTH in it, open it in a text editor, look at it’s syntax, and modify a copy of the Ultralibrarian file so the syntax matches.
Also, KiCad V6 is getting a bit old now. KiCad V8 has been released a few months ago, and updates are similarly priced to your original KiCad purchase.
@Paulvdh Thank you, actually I meant to mod that post, the error is that the file has four double quotes instead of 2 in the number field. Kicad was telling me it wants to see pad designator in position 11, that is where the third quote is. So the error message was a little confusing also. (The extra quotes get disappeared in the post.)
WIll kicad8 accept my kicad6 projects and parts directories?
About the double quotes:
I just ignored them. This forum software does some weird auto formatting, and I was not sure what is going on there. It also does not influence my answer: Just parrot the syntax from a working example.
Kicad can open older projects. With a V6 projects I do not expect any problems (Either with a project or a library). With older projects, it depends on the state of the project. (For example, people used to have a very nasty habit of deleting the [Project]-cache.lib file, while it is an essential part of a KiCad V5 project, and it’s needed to convert the project to V6 or newer). A KiCad V4 project depends on the availability of the original libraries the project was created with.
Starting from KiCad V6 all information of the project is defined in the project itself, and upgrading to newer KiCad versions should require very little effort.
For the currently supported versions (38-40 and rawhide) there is stable 8.0.1 (perhaps even 8.0.2 by now) and via copr you can get stable earlier as well as testing (that will become the next 8.0.x stable) and nightly development versions (8.99).