SRB Thrust effect displaced to one side

[BasharMilesTeg]

If a pSRB is attached to the rocket by its bottom node the thrust effect is displaced out to one side and it does not produce thrust. This does not occur if it is attached radially or by its top node. I've attached an output log and screenshot where I first attach a pSRB to a capsule by its top node and it works as expected, revert then move the pSRB to be attached by its bottom node (the 'bell end') and the bug occurs.
This was tested using a minimal RO install using only required mods installed by CKAN.

[ItMustBeACamel]

Thanks for the report. The problem also appears on a stock install. There is a Null Reference in the ProceduralSRB module if something is attached to the bottom.

edit:
Seems like the bug only appears if the stack attached to the bottom contains the root part