Plugin upgrade 4.0 to 4.3 error

I am trying to move a plugin I developed in 4.0 to 4.3.
I made adjustments for 4.3 changes and published to test server.
When I click "Install" I get message that plugin has been installed.
However the system log (pasted below) says plugin is NOT installed.

Is there any tricks to try figure out which constructor is causing the issue?

The plugin "Widgets.LHst" not installed
Full message  
Nop.Core.NopException: No constructor was found that had all the dependencies satisfied.
---> Nop.Core.NopException: Unknown dependency
   at Nop.Core.Infrastructure.NopEngine.<ResolveUnregistered>b__15_0(ParameterInfo parameter) in C:\VS_workspace\N_4.30_MEBulbs\Libraries\Nop.Core\Infrastructure\NopEngine.cs:line 249
   at System.Linq.Enumerable.SelectArrayIterator`2.ToArray()
   at Nop.Core.Infrastructure.NopEngine.ResolveUnregistered(Type type) in C:\VS_workspace\N_4.30_MEBulbs\Libraries\Nop.Core\Infrastructure\NopEngine.cs:line 245
   --- End of inner exception stack trace ---
   at Nop.Core.Infrastructure.NopEngine.ResolveUnregistered(Type type) in C:\VS_workspace\N_4.30_MEBulbs\Libraries\Nop.Core\Infrastructure\NopEngine.cs:line 262
   at Nop.Services.Plugins.PluginDescriptor.Instance[TPlugin]() in C:\VS_workspace\N_4.30_MEBulbs\Libraries\Nop.Services\Plugins\PluginDescriptor.cs:line 67
   at Nop.Services.Plugins.PluginService.InstallPlugins() in C:\VS_workspace\N_4.30_MEBulbs\Libraries\Nop.Services\Plugins\PluginService.cs:line 469

Did the plugin install when you tested it in development ?

I am attempting to publish to my development server.
Are you asking if I ran it inside VS?
I will have to find out how to do that.

Artdtc wrote:
Yes but sometimes it can be trick to set breakpoints depending on the nopComemrce version

The install will be calling you Install routine in the plugin so you can start there

Are you creating tables - If so check that code
Are you calling your own services - If so are they installed in the DependencyRegistrar