Sitecore upgrade from 9.0.2 to 9.3 issue

Question

I have upgraded our sitecore application from Sitecore 9.0.2 to sitecore 9.3. However when i try to run my application i get the below error. I also tried try copying all the dll's from bin folder from vanilla sitecore 9.3 to my application,but still this issue exists.

Can someone please help.

Method not found: 'System.Web.HttpContext Sitecore.Pipelines.HttpRequest.HttpRequestArgs.get_Context()'.

Stack trace :

[MissingMethodException: Method not found: 'System.Web.HttpContext Sitecore.Pipelines.HttpRequest.HttpRequestArgs.get_Context()'.]
   Unicorn.ControlPanel.UnicornControlPanelPipelineProcessor.Process(HttpRequestArgs args) +0
   (Object , Object ) +14
   Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args) +484
   Sitecore.Pipelines.DefaultCorePipelineManager.Run(String pipelineName, PipelineArgs args, String pipelineDomain, Boolean failIfNotExists) +236
   Sitecore.Pipelines.DefaultCorePipelineManager.Run(String pipelineName, PipelineArgs args, String pipelineDomain) +22
   Sitecore.Web.RequestEventsHandler.OnPostAuthenticateRequest(HttpContextBase context) +218
   Sitecore.Nexus.Web.HttpModule.‪‏‪‌‪‍‌‮‬​‬‍‎​‏‍‪‭‎‌‍‪‪‮‮(Object , EventArgs ) +207
   System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +223
   System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step) +213
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +91

Answer 1

Looks like it might be a problem with Unicorn. In 9.3 Sitecore removed the Context property from the pipeline args, but your older version of Unicorn is trying to access it. They have fixed this though, so I'd remove the Unicorn config files and dlls and verify the site works ok, and if it does then apply the most recent version of Unicorn.