Start a normal playing session, click on a cracked brick wall.
Now open the editor and remove the wall which tux was going to smash.
Resume to game, and it crashes:

 Program received signal SIGSEGV, Segmentation fault.
0x0000000000002e64 in ?? ()
(gdb) bt full
#0  0x0000000000002e64 in ?? ()
No symbol table info available.
#1  0x000000000043e3e3 in ?? ()
No symbol table info available.
#2  0x00000000008d8b8c in ?? ()
No symbol table info available.
#3  0x000000000043af81 in ?? ()
No symbol table info available.
#4  0x0000000000000000 in ?? ()
No symbol table info available.


Indeed this is not very likely to happen in every-day-usage, but IMO it should
get fixed because its a crash.

Perhaps resetting the mouse move target as we resume playtest is a good way to
fix this?

 r5036

I can't reproduce this issue. Is this still reproducible for you ?

Why would you think about doing that? :-)

Looks like when starting a playtest, you need to set:
Me.mouse_move_target_combo_action_parameter = -1;
(as otherwise it has the index value of a suddenly non-existant obstacle)

Matthias is a very dedicated tester. Why he would think about doing it beats me,
but he's right that crashes have to be fixed.
A hack is not welcome - resetting the mouse move target is the proper solution IMO.

Seems to be fixed by now. :)