well you need to explain exactly when appear the error,
may be you did not copy the file xml , blogger needs xml file for to reads correctly the template;
You need to follow the next steps:
1. click on download
2. then appear a small window you neet to click on “open”
3. then you need to click “Copy” on the xml file with the rigth bottom of your mouse..
4. and Finally you need to paste the xml file into a folder on you computer.
When you have the XML folder save on you computer you need to go to html edition click on browse , find the xml file on your computer, and then upload it,
Ps; i forgot tell you need to copy the header picture too, when you open the file there is three files: header picture, xml file, and readme file,just copy the header and then paste it to you computer;