I have a loop with two "Chemistry External tool"-nodes. I wary the parameters for the first node using flow variables and sometimes this node will not produce any output and give a "Output 1 has no data in output port" error message. This does not seem to be a problem as the flow continues anyway.
But when I feed the output data from the first node into the second node this node can not run and I get an "Execute failed: Output files not found."-error which stops the loop.
Is there some generic way to solve problems like this?