All custom brushed missing

[A_A_Photography]

I was working as usual but when I opened Photoshop today all my custom bruhses were gone.
They are not in the folders or whereever.

Also I cannot create new brush presets as then an error-message will appear that my selection is empty (although I am doing it as all the time I'm creating brushes (from .png)). What is going wrong here? I did not update/delete/change anything since the last time I opened Photoshop (CC2020).

Please help

[melissapiccone]

I have all of my custom stuff saved in a library. I have a library for brushes, one for styles, etc. I don't know what your workflow is, but you should always save your custom stuff away from Photoshop. I have a folder called Adobe Extras on Dropbox. I've had this folder longer than Dropbox has existed. All of my custom presets are in there, some going back to the 90's. 

As for your error, make sure you are on the right layer. If still having problems, I recommend resetting preferences. 

[A_A_Photography]

I appreciate your effort in writing that answer, but how is this going to help me with my problem? 
Double checked everything, reinstalled again without deleting previous custom folders. Of course I am on the right layer. 

[melissapiccone]

Sorry my answer wasn't helpful. Hopefully somone else will pop in and help.