sharepoint 2010 entity (external content type) cannot be found with namespace =

I was getting this error after redeploying a solution with BDC model. There are few ways described in below posts about fixing them, but in our case they did not work

http://www.sharepointing2010.com/2013/09/restore-bcs-ect-external-content-type.html

http://sharepointpromag.com/sharepoint/deploy-vs-business-data-connectivity-model-solution-sharepoint

Finally, we exported the BDC model from dev server central admin site and imported it on the live server central admin site which worked fine...

There might be a better and more ideal solution available to this problem, but for now we are relieved.