Back-up your project to your computer before anything else.
To find out if the Sensor component is the problem, just delete it!
It would help to see your BLE Blocks too. From the top right-hand corner of App Inventor, temporarily change the language to English. Then right-mouse in the Blocks work area and select "Download Blocks as image".
Thank you very much for your quick response. I have tried the version that Tifòn has indicated and it has worked the first time. It no longer gives an error. I think that the second option is not necessary so I will continue with the project and if I have errors again I will do as you indicate and I will send you the information that you mention.
Regards