Hey @mr_fanatic,
Do you see any error in browser console? You can use Command+Option+J (Mac) Control+Shift+J ( Windows /Linux ) to open the console in chrome browser.
Check for any errors in console tab, and post it here.
Thanks, Umesh
@umeshsingla, there is no error in console.
Hey @mr_fanatic
Did you try to open the console log in Chrome and after that to dismiss the notification?
If not, please do so and let us know, if there’s any error message in there.
If so, then could be happening due to some conflict with another plugin/theme, so you should perform a conflict test on it.
How to:
– backup your site
– deactivate all plugins apart from Smush
– activate a default theme like TwentySeventeen
– try to dismiss the notification message
Reference:

Warm regards,
Dimitris
Hello @mr_fanatic,
it’s been a while since we’ve heard back from you, so I mark this topic as resolved. Feel free to post back here, if more assistance is required and we can re-open it and continue troubleshooting. 🙂
Warm regards,
Dimitris