I have made a workbench that contains an Emailer. I did not notice this directly, but the Emailer is a Package.
I saved the workbench to a network location so my colleagues can run the workbench as well. And wrapped it in a Workspace Runner workbench so the workbench is not open for editing when colleagues run the workbench.
But since this year I notice that the WorkspaceRunner fails because the Emailer package is not installed. This Emailer is installed as soon as the Workbench containing the Emailer is opened.
My workaround now is adding a Emailer Transformer to the WorkspaceRunner workbench so the Emailer is installed when this workbench is opened.
Hope this helps others that use WorkspaceRunners and Packaged Transformers in there workbenches.