Hi Yokesh

I'd try to contact the developers of the widget. Perhaps open a ticket here: https://github.com/ananthiatthimuthu/ReactImageMapper.

But to fix it, go to your project directory, then widgets folder, identify this widget and unzip it to a folder.

Then go the uzipped folder > src > ReactImageMapper.xml file and remove this part from the xml (Documentation: Pluggable Widgets Property Types):

allowNonPersistableEntities="true"

After, from the terminal, rebuild the widget with "npm run build" and replace the newly built widget (in the dist folder) with the existing .mpk file.

In Studio Pro, go to App > Synchronize Project Directory and this should fix it.

Not the most straightforward solution, but should get you going. 

Please accept this answer if it helps.

Best regards,

João