No package found with specified pattern: D:\a\r1\a\**\*.zip

For anyone else experiencing this problem using Azure DevOps, it's useful to turn on debug mode. For your release, define the pipeline variable System.Debug with value true. That gave me this output which was much more useful:

Now at least I know it's on my target VM and the path is probably wrong.

In my case (build .sln with c# project from azure git) the build was saving the package in D:\a\1\a\ folder (instead of r1\a) and I wasn't able to edit the build steps in the UI so I edited the newly added azure-pipelines.yml file and added one more task at the very end:

- task: PublishBuildArtifacts@1

This copies the .zip package to a "drop" location (r1/a) which the Release Pipeline expects.

​And now the Release Pipeline is finding the file in r1/a folder.

You can't use wildcards for folder names unfortunately, only for file names. If you're using a 'Copy Files' build task you can put this value in 'Source Folder':
D:\a\r1\a\

and this value in 'Contents':
**\*.zip

Or you can put the full file directories with *.zip. Good luck.

If you are using "Azure App Service Deploy" task, set the "Package or folder" path to: $(System.DefaultWorkingDirectory)\InnovationInABox-CI\drop\s\build.