I had this same issue whilst doing some POC work. I was able to overcome it as follows:

1. Navigate to Workflows | Jobs & pipelines.
2. Select your pipeline.
3. Click the drop-down next to the Start button.
4. Choose "Full refresh all".

That resets it all and fixes the problem caused by deleting rows (in my case, all the rows) from the bronze table (which broke the silver table load in the pipeline, but it's fine after full refresh operation). It might not be these best solution for everyone's needs because it'll force a full reload from scratch and maybe you don't even have all your historic source files/messages available anymore.