The download does not have an extension. IE: ots, otc
Other template downloads do have extensions.
Libre Office does not seem to recognize the file I downloaded/
The issue has something to do with the templates website. It happens with some but not all templates on the site. Right-click on the download link and choose Save Link As…, in the filename field paste or type this text (including the quotes): “simple-service-invoice.ots” Press enter and the template will download correctly. To open it, open the download location and double-click the file as you normally would. If you want to have it show up in your templates folder, click File - Save as template…, then click Save. Type the name of the template and click Ok. You can then find it by going to File - New - Templates and click on the Spreadsheets tab.