Material doesn't show in Unreal's content browser


I created a material yesterday and everything was working fine, but when I opened my project today the material doesn’t show in Unreal’s content browser, but it shows inside the contents folder of the project. I tried closing and reopening the project but the material doesn’t show. Also I tried putting other files in the contents folder and they all appear in the content browser except for this particular material(I tried other .uasset files and materials as well and they worked). I don’t remember changing anything yesterday before closing the project and I’m sure I have saved it.
The material was created in Unreal Engine.

Thank you in advance.