Issue PowerPivot Data Refresh with SharePoint 2013

Issue PowerPivot Data Refresh with SharePoint 2013 

Issue-Not able to Refresh the excel report in Browser and in excel as after migration of Report from one server to another the workbook connection was taking old connection string.
2.Secondaly It was Not allowing to  Edit\Change Excel Workbook Data connection string.

Issue Description- One of my excel 2013 power pivot report was migrated from old server to new server after migration i changed the excel power pivot connection string to connect with new server but the workbook connections was still taking the old connection string of old server and there is no option of changing workbook connnection string .
While opening the powerpivot data connection window it was only allowing to view the workbook connection however i was able to edit the powerpivot connection but it was not updating the workbook connection screenshot below screenshot.

Issue Solution: Searched  a lot in but didn't get any solution so below is the solution what i did to fix.

1.Select the complete sheet Ctrl+A 
2.Copy the Sheet Ctrl+C
3.Open new excel in new window 
4.Paste your Excel Sheet data into new Excel sheet(don't paste the data in same excel file(new sheet )
5.It will automatically copy the sql code in back end and will connect string along with excel data in new excel file.
6.Save the File and replace it with your old existing Excel Report.

Preview the Report in Excel as well as in browser the report will Refresh the Data without any Issue.
Also if you will see the workbook connection it will have same connection as power pivot connection file.

Note:In case you are getting below errror while  refreshing the data in Browser

For this Issue open Report in Excel 

Go to Data tab

Connection Properties

Authentication Setting

Change None to-Autheticated User Account.

Save the Excel Report and Refresh again in browser it will refresh the data.