No problem; it looks like you just mixed up the installation process for the commands and the custom UI.
It seems you've already installed your commands, so just go for fixing the custom ui. I'll put the links in case you need them.

To install commands, follow the guide here:
https://moi3d.com/faq#Q:_How_do_I_install_a_plug-in_script.3F
For example, the edgeFlange.js and edgeFlange.htm files should go directly into the "commands" folder.

To install the custom UI, follow this instruction:
https://moi3d.com/forum/index.php?webtag=MOI&msg=6507.268

Take your time and try again. You'll see it's quite simple once you get the hang of it.

Hi Mala,
I will attempt to help with my observation.

I think the error for you comes from extracting "Zipped" or "compressed archives"

I have created a sample file for you to test with. A Zip file which contains only 1 single, text document named "1.txt"

You can test HOW you are extracting the contents of the file!

There are usually "2 ways" that the extraction happens. Your choice matters.

in Winzip or Winrar, the options are these:

1. Extract Files

2. Extract to 1

3. Extract Here

The first 2 methods create a folder named the same as the contents, with the contents inside that. So a folder named "1" appears, with the 1.txt file inside of that.

The last method, #3, Extracts the Contents (a single "1.txt" file) to where you chose

So with this file, experiment with how you extract it and realize when and where you get the "contents" of the zipped archive! A single text file.

With most of plugins. the "contents" are usually a js file and an htm file.

With things like custimui, make sure the folder extracted is the "contents" and not a folder named as the zip.

Hope this helps

And here is one more to add to your testing:

a zip file named "Mala's Archive created for testing1"

In this zip file is a folder named 1

In the "folder named 1" is a text file named "1.txt"

Practice to get a folder named 1, with a single text file inside of it.