I am trying lo level up a wizard to level 11 but when I select two spells the finish button remains grey. It has a hint saying "None of your spellbooks contains enough room to scribe these spells. You must acquire a new spellbook to complete the level up sequence."
As far as I can tell you have added a new rule and then failed to document it. Nothing in the ui for a spell book says what its limit is or how full it is. It doesn't even list the level of the spells so working it out manually will be a tedious process.
The wording implies you can skip the spells and come back later to get them but I can't see a way to do that.
An additional issue is that when leveling up it doesn't tell you what spells were selected. If you select auto at 7th level or higher good luck working out which spells it picked.