Error at executing Azure Pipeline for a .Net Desktop App - Azure DevOps

I'm creating my first Pipeline to build a .NET Desktop application. I have added the needed task to my YML file but I'm getting the following error, regarding an assembly that may be missing or not found.

Error Message: "The type or namespace name 'AxAcroPDFLibre' could not be found..."

Screenshot of error

This is the complete code of my YML file:

# .NET Desktop
# Build and run tests for .NET Desktop or Windows classic desktop solutions.
# Add steps that publish symbols, save build artifacts, and more:
# https://docs.microsoft.com/azure/devops/pipelines/apps/windows/dot-net

trigger:
- master

pool:   vmImage: 'windows-latest'

variables:   solution: '**/*.sln'   buildPlatform: 'Any CPU'   buildConfiguration: 'Release'

steps:
- task: NuGetToolInstaller@1

- task: NuGetCommand@2   inputs:
    restoreSolution: '$(solution)'

- task: VSBuild@1   inputs:
    solution: '$(solution)'
    platform: '$(buildPlatform)'
    configuration: '$(buildConfiguration)'

- task: VSTest@2   inputs:
    platform: '$(buildPlatform)'
    configuration: '$(buildConfiguration)'
     
- task: CopyFiles@2       displayName: 'Copy Files to: $(build.artifactstagingdirectory)'       inputs:    
    SourceFolder: '$(system.defaultworkingdirectory)'    
    Contents: '**/bin/**'    
    TargetFolder: '$(build.artifactstagingdirectory)'       condition: succeededOrFailed()
       
- task: PublishBuildArtifacts@1       displayName: 'Publish Artifact: drop'       inputs:    
    PathtoPublish: '$(build.artifactstagingdirectory)'       condition: succeededOrFailed() I found this similar question here on StackOverflow, but I have checked my nugget package command and I have it in the build file.

At the end of the process, the job fails.

Click here to see error log

Right now that's all I've tried since I'm documenting myself on Azure DevOps Pipelines. If you have any recommendations I will appreciate them.

This has nothing to do with your pipeline as such, it is failing to build your solution, so there is a missing dependency or package that is not present on your build agent.