Bluetooth problem with MBOT

Hi,
We make an app who control Mbot1 with bluetooth ( we use .aix from Makeblock http://appinventor.makeblock.com/com.makeblock.appinventor.MBot.aix) and for no reason , we have an issue which didn't exist one month ago.
If , we use an app make one month ago : No problem but if we make it again (the same) and take the apk, we have the error that you can see in pictures.


So we think that the problem is not form our side.
thanks for reading