Union Tool Errors

[sufregs]

See below snapshot of workflow

I have a Union tool that is fed from multiple other union tools. The upstream union tools are fed from the outputs of different containers. When i disable a container, so that it does not run, the downstream union tools throws an error Union (528): Missing Incoming Connection. I tried back tracing and discovered that None of the upstream Union tools are giving an output even though they all have text inputs with data (string) connected to them. 
I have tried using the Detour and Detour end tools so I do not have to disable the containers, but the tools (select, formula, etc.) also throw errors because they expect an input. Is there a way around this?

[sufregs]

Thanks. 

Double checked the Union config, it's same as yours. Not forcing errors to be thrown. 

I'll keep troubleshooting

[sufregs]

Hi Jimmy

Thanks for your response and help. I do have AMP enabled. I turned it off while troubleshooting and created the workflow I shared while it was turned off hence those errors. I have re-enabled it.

To answer your questions

1. Yes it is. (I was about to give a reason why but have just discovered that it does not achieve my aim. Thanks for catching that.) I wanted the user to be able to modify that sheet and the flow use the updated version when run the second time.

2. Noted on the detour tools and control containers. The detour start outputs are connected. See attached updated workflow

3. The reason I opted for control containers was to ensure sequential run of the workflow. I later discovered that it didn't meet my end goal because I still got errors on excel file being locked by another process (all the containers output to different sheet of the excel file)

[apathetichell]

@sufregs have you followed my instructions to mandate schema? are you using any python tools/connectors in your containers?