I'm unable to prepare or unprepare any spells in the editor or at the character sheet. The only thing i can do is to learn or delete spells ... but not prepare or unprepare spells. I cleared my cookies and also tried it in incognito mode in Chrome or Firefox ... 

My character is a level 18 wizard and up until now i have always been able to prepare or unprepare my spells using the spellbook. But for a few days now, this hasn't been possible anymore. I can only add(learn button) or delete the spells from my spellbook ... not prepare/unprepare

From what I can tell, this is a UI bug, not a functional bug (I came to the forum to raise this issue too).

Functionally, the "DELETE" button in the Spellbook sidebar will actually un-prepare the spell. Similarly, the "LEARN" button in the sidebar will actually "PREPARE" the spell. You'll probably note that in your list of Prepared Spells, the button now says "DELETE" too.

It's certainly a bug, it's really bad from a UI and UX perspective, but thankfully the functionality has not been completely broken.

Note: spells can still be deleted from the spellbook in the usual way, by opening the spell description and using the "DELETE" button at the bottom (which is displayed next to a correct "PREPARE(D)" button.)

Example Wizard displaying this issue: https://www.dndbeyond.com/characters/27172838/L0SMoA

Ah it worked! Thank you :)

this label bug has existed for months now will it ever be fixed...?

Will this label bug for the Wizard Spell book for Add, Prepare, Learn spells ever be fixed? It is confusing new players who have never played a Wizard before.