Question: When i open my SharePoint Designer i get the following error:

[![enter image description here](https://i.stack.imgur.com/Wc2f5.gif)](https://i.stack.imgur.com/Wc2f5.gif)

What should i do to resolve it.

Answer: 
To solve the issue, you can try the steps below and share with us the outcomes:

1. Restart your SharePoint Designer 2013 and re-try to open the site.
2. Clear the SharePoint Designer cache via the steps in the thread:
[How to Clear Your SharePoint Designer 2010/2013 Cache](http://www.c-sharpcorner.com/UploadFile/sagarp/how-to-clear-your-sharepoint-designer-20102013-cache/)
3. Reinstall the application via this location : 
[SharePoint Designer 2013](http://www.microsoft.com/en-us/download/details.aspx?id=35491)
The location where we enter the URL did make a difference for me. Please see image below.

[![enter image description here](https://i.stack.imgur.com/dQ6rN.png)](https://i.stack.imgur.com/dQ6rN.png)