Plugin updated from 4.00 to 4.20 - installation problem

Hi. I updated a Plugin from NOp4.00 to 4.20.

I can't test the plugin installation in Vstudio Debug because the new installation process restart the appPool: i don't know how solve this to debug plugin installation.

By the way, i solved all compile problems; during installation i received this error:
System.NullReferenceException: Object reference not set to an instance of an object.
   at Nop.Plugin.Misc.MystonesEasyFatt.MystonesEasyFattPlugin.Install()
   at Nop.Services.Plugins.PluginService.InstallPlugins() in C:\Users\max\Documents\Visual Studio 2017\Progetti\nopCommerce_4.20_Source\Libraries\Nop.Services\Plugins\PluginService.cs:line 419

Can you help me?

1. Click plugin Install button in plugin list.
2. Stop debug mode in Visual Studio. (DON’T CLICK Restart application to apply changes button)
3. Run application in debug mode from Visual Studio.

Right after running the application, it will start applying changes (install/uninstall) in plugins.

I was having similar problems too.
Thank you mhsjaber!

mhsjaber wrote:

It seems that this doesn't work for me ... Do i exceute the first step in Debug Mode ?

Thanks in advance

mystones wrote:

Not mandatory.

Hi. It works. I forgot to answer you. Thanks