This can happen when there is a Cached version of the page saved within the Chrome Browser.
To Clear the Cache
On your computer, open Chrome
At the top right, click More
Click More tools
Select Clear browsing data
At the top, choose a time range. To delete everything, select All time
Next to 'Cookies and other site data' and 'Cached images and files' check the boxes
Click Clear data
Return to Insights, Re-Run the report and try to Export