Yes. Unfortunately, the command succeeds in it for me [Acad2020 here -- I can try with a later version elsewhere later]. That makes it pretty impossible to trouble-shoot. Since the problem seems to be in the joining, it could be that the JOIN functionality has been altered in some more recent version, so that these lines
(initcommandversion); [to accept initial multiple selection]
(command "_.join" toJoin "")
might need to be done differently.
EDIT: A remote possibility:
See these lines in the original:
(mapcar 'setvar svn '(0 0 0 1 "ANSI31" 0.005 0.0))
;; turn off Osnap, command echo, blips, set PEDITACCEPT &
;; Hatch properties <-- EDIT pattern name, scale, rotation [last 3 above]
Your sample drawing indicates that you have edited that to use 0.5 as the HPSCALE setting, changed from the original 0.005 [which was a part of the original request]. Is it possible that in editing that, you accidentally changed or deleted something else that might affect the operation?
Further EDIT:
I just opened the version as posted at Message 48, and I see that HPSCALE setting has not been changed. I think that must mean you changed the scale of the patterns in the sample drawing after using the command. Losing the possibility of mis-editing leaves me at a loss for an explanation, but it seems to be JOIN-related, since your red boundaries where it goes wrong are not the single Polylines that they ought to be, and that they become when I try it.
Kent Cooper, AIA