/mode1.lua:42: bad argument #3 to 'format' (number expected, got nil)

[gui7545]

Hello,
I still have a problem with BGA, It is about the end of the unloading part of the unloading. The vehicle takes the road speed but the trailers is not empty yet.
Fortunately, i have a error in the log:

Error: Running LUA method 'update'.
C:/Users/Guillaume/Documents/My Games/FarmingSimulator2015/mods//ZZZ_Courseplay/mode1.lua:42: bad argument #3 to 'format' (number expected, got nil)

I use version 0.207

Here is a screenshot: