1. Type in Service.msc in Run Command.
2. Once the Servcies App is opened. Look for MySQL57 Service. And restart it.
![](https://www.aspsnippets.com/Handlers/DownloadFile.ashx?File=14ac92cf-383c-423b-bf88-8eff050b9d6a.png)
3. Then open MySQL WorkBench and in your database run the following SQL.
Where AjaxSamples is name of my Database.
use AjaxSamples;
set global optimizer_switch='derived_merge=OFF';
![](https://www.aspsnippets.com/Handlers/DownloadFile.ashx?File=d9adbc9e-8f00-4b24-991e-6c85db9d0cab.png)
4. Restart the MySQL57 Service again.
5. Now in Visual Studio, Right Click and update the edmx and finally save it.
![](https://www.aspsnippets.com/Handlers/DownloadFile.ashx?File=c0805282-7e89-4a60-90f7-b459324c60f6.png)
Reference: StackOverFlow