Importing Theme Settings

I have exported my theme settings to use on another site. I understand it will over write the settings on the existing site. I have a few questions:

Can you give me a list of things it will over write, so I can decide if I want to do this or if it would be ok and I can just go in and make the changes I wanted after the import?

Though, I tried to import the theme setting and I get this error:
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TCWebite – Enfold-theme-settings-2018-11-12.txt
HTTP error.
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What is this and how do I fix it?

Thanks..

Gene