Multi-instance (parallel) external tasks are getting stuck - JavaScript edition

[LukeSWK]

I was experiencing the same issue. Here is the solution:

Multi-instance External Tasks are getting stuck

We had the same issue (multi-instance subprocess stuck) and found that the cause was that we were overwriting the loop control variables. Instead of calling complete with task.getVariables() as argument, try providing only those variables that you want to change. -Hans