In ReLoop.fmx in AttributeCreator_3 you set _count = @value(_count_+1 which should be @Evaluate(@Value(_count)+1).

@nielsgerrits Thanks for the feedback. I updated as you said, but it is still infinitely looping. Did you get it to run to a set number of iterations? Thanks so much for the help. 

Attached a sample you can use to build on.

@nielsgerrits Thanks!! That is the demo I used to build the original loop I uploaded. I still can’t understand why the data is not looping for me. 

My data enters the loop as expected through the ‘Input’ port and passes through my process. It then goes through a tester, if it fails the tester it is set to loop again. However, this data never reaches the ‘Looped’ port. Even though I know for a fact there is data failing the tester. 

I just can’t figure out why it’s not going back to the loop. Thanks

Not sure why but I have issues installing your custom transformer so I can’t reproduce what you have. In general it pays off to make small steps when iterating and developing a workspace. This is a but cumbersome with a custom transformer but I think this is what you need to do.

@nielsgerrits I tried building the whole loop transformer from scratch and am still getting the same error. I have attached a new version of the workspace/data/loop to see if there is a chance you can replicate the error. Thanks for all your help. :)