Describe the bug
I moved accidentally the column block in itself. The editor crashes an error message I can't fully read because it redirects me to "about:blank".

To Reproduce
Steps to reproduce the behavior:

1. Add column block
2. Do not add any blocks to the columns
3. Move the column block in one of the column spaces
4. BOOM.

Expected behavior
I should not be able to move the column block in itself.

Screenshots
N/A

Desktop (please complete the following information):

• OS: macOS High Sierra 10.13.6
• Browser: Firefox
• Version 65

Additional context
WordPress 5.0.3