“Airbag defective” and service light

Hello together, I have a problem with my Renault mode 1.2; Bj 04-05 After I fixed a cable of the rear light to the right, because it had a wobble contact, my car shows the message “Airbag defective”, with airbag light and service light. So I was in a well-known workshop today and had the error read out. Here another variety of errors occurred, which may be due to the electronics problem with the rear light. (The Rücklic Ht flashed in all colors and shapes when I braked and flashed at the same time).All errors could be deleted except for the error: Airbag CAN error code 36887: Gutstraffer rear -> circuit faulty (see picture) error code.png Does anyone have any idea what that can be and how to fix it? Master told me that a harness can cost 200 euros fast. Is it just a stupid coincidence, or can it really be related to the taillight? Mfg OrangeGER