Nested custom `content: 'none'` blocks throws an error

[mfanselmo]

Describe the bug When using an custom block set with content: 'none', and creating it from the slash menu it throws an error.

To Reproduce A basic custom block https://stackblitz.com/edit/github-a6kavu?file=Separator.tsx Video of the issue: https://github.com/TypeCellOS/BlockNote/assets/26393563/2a191ead-07ed-47dd-8f89-9440a3810ea6

Misc

• Node version:
• Package manager:
• Browser: Safari
• [ ] I'm a sponsor and would appreciate if you could look into this sooner than later 💖

[YousefED]

Thanks for the clear reproduction, this seems like a bug indeed and we'll look into it!

What are you using BlockNote for btw?

[mfanselmo]

Thanks for the help! I am building an ELN (Electronic Lab Notebook), which will rely heavily on custom blocks from https://github.com/TeselaGen/tg-oss. So far so good except a few old dependencies we were using which we had to update. Once we launch it I will gladly share it with the community

[nperez0111]

This code works in the latest version, not sure when it was fixed