Server crash when loading .mts file

[Sur3]

Hi my server crashed when trying to load a .mts file via the save/load menu:
2018-06-17 14:00:53: ERROR[Main]: ServerError: AsyncErr: ServerThread::run Lua: Runtime error from mod '' in callback on_playerReceiveFields(): ....minetest/mods/worldedit/worldedit_commands/init.lua:1209: attempt to concatenate local 'count' (a nil value)
2018-06-17 14:00:53: ERROR[Main]: stack traceback:
2018-06-17 14:00:53: ERROR[Main]: ....minetest/mods/worldedit/worldedit_commands/init.lua:1209: in function 'func'
2018-06-17 14:00:53: ERROR[Main]: ...etest/mods/worldedit/worldedit_gui/functionality.lua:731: in function <...etest/mods/worldedit/worldedit_gui/functionality.lua:722>
2018-06-17 14:00:53: ERROR[Main]: (tail call): ?
2018-06-17 14:00:53: ERROR[Main]: /usr/share/minetest/builtin/game/register.lua:412: in function </usr/share/minetest/builtin/game/register.lua:392>

[sfan5]

.mts file have to be loaded using //mtschemplace instead, which is not available in the GUI menu.