java.lang.NullPointerException
at logisticspipes.request.RequestManager$workWeightedSorter.compare(RequestManager.java:67)
at logisticspipes.request.RequestManager$workWeightedSorter.compare(RequestManager.java:37)
at java.util.TimSort.countRunAndMakeAscending(TimSort.java:324)

line 67 is c = o1.destination.getCachedPipe().getLoadFactor() - o2.destination.getCachedPipe().getLoadFactor();

Okay, so definitely something to check.

Is this still an issue?

i havnt seen this recently, but i also havn't been playing with a large network.

If no changes have been made to the pipe handling code, then the chunk/pipe can still fall out of cache while the check is going on and NPE.