XSLT Error message

I have MAC and running MAC High Sierra version 10.13.6. I tried to download a template and got an error message. Anyone know how to fix that?

Thanks

Sorry? What template you’re talking about?

Builder something that is offered when you download the program for the 1st time?

Sorry, but I can’t say that I understand what do you mean. Please consider adding some more context to your messages. Thanks.