Firmware update orbi rbr40

I was able to update my Orib RBR40 router to RBS40-V2.6.1.36.img however when updating to RBS40-V2.6.1.38.img, I get an error

"400 Bad Request

This server does not support the operation requested by your client. "

I tried using Microsoft Edge as another thread recomended and there is no difference.

I connected via an ethernet cable to the router.

Do I need to factory reset the router in order to be able to update to this version!