[Deprecation] Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience.

Hi I'm stucked on the unit management part. Whenever I try to manage cost I have a popup window which I guess is use to change the cost of the unit for this particular date, but it's missing part of it (again I guess). see attached docs.

I also added the error within the console.

Any help?

Modules are updated
All libraries installed
Status report clean

Thanks