Drag and drop multiple blocks into container breaks editor

[lesleysim]

​http://somup.com/crivq7Yzif

I recently found a bug in 5.8 where dragging and dropping a group of blocks into a container (e.g. a column) breaks the editor and results in this error:
The editor has encountered an unexpected error.

Notes:

• I'm using v.5.8
• Steps to reproduce the problem: Create a new post. Add more than 1 paragraph block with text. Add columns block. Add text to columns block. Select paragraph blocks. Drag and drop them into columns block. The editor will break.
• The problem occurs on a fresh install of WordPress 5.8 with no plugins.
• The expected result is to be able to have paragraph blocks successfully dragged into the columns block. Instead, the editor broke.

Here is the error that shows up in the console:

TypeError: e is null
    pp http://wptest1.local/wp-includes/js/dist/block-editor.min.js?ver=390a9f83b606a55e8b523c4d16bdb08c:12
    gp http://wptest1.local/wp-includes/js/dist/block-editor.min.js?ver=390a9f83b606a55e8b523c4d16bdb08c:12
    Bh http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:126
    Dj http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:162
    unstable_runWithPriority http://wptest1.local/wp-includes/js/dist/vendor/react.min.js?ver=16.13.1:25
    Da http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:60
    xb http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:162
    Te http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:146
    Pg http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:61
    unstable_runWithPriority http://wptest1.local/wp-includes/js/dist/vendor/react.min.js?ver=16.13.1:25
    Da http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:60
    Pg http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:61
    ha http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:60
    Ja http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:224
    ch http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:93
    e http://wptest1.local/wp-includes/js/dist/data.min.js?ver=7bfa3a673439e85e459d5ec92d30fdda:2
    t http://wptest1.local/wp-includes/js/dist/data.min.js?ver=7bfa3a673439e85e459d5ec92d30fdda:2
    v http://wptest1.local/wp-includes/js/dist/data.min.js?ver=7bfa3a673439e85e459d5ec92d30fdda:2
    b http://wptest1.local/wp-includes/js/dist/data.min.js?ver=7bfa3a673439e85e459d5ec92d30fdda:2
    i Redux
    A http://wptest1.local/wp-includes/js/dist/data.min.js?ver=7bfa3a673439e85e459d5ec92d30fdda:2
    L http://wptest1.local/wp-includes/js/dist/data.min.js?ver=7bfa3a673439e85e459d5ec92d30fdda:2
    dispatch http://wptest1.local/wp-includes/js/dist/data.min.js?ver=7bfa3a673439e85e459d5ec92d30fdda:2
    Redux 17
    A http://wptest1.local/wp-includes/js/dist/data.min.js?ver=7bfa3a673439e85e459d5ec92d30fdda:2
    L http://wptest1.local/wp-includes/js/dist/data.min.js?ver=7bfa3a673439e85e459d5ec92d30fdda:2
    f http://wptest1.local/wp-includes/js/dist/data.min.js?ver=7bfa3a673439e85e459d5ec92d30fdda:2
    ss http://wptest1.local/wp-includes/js/dist/block-editor.min.js?ver=390a9f83b606a55e8b523c4d16bdb08c:12
    us http://wptest1.local/wp-includes/js/dist/block-editor.min.js?ver=390a9f83b606a55e8b523c4d16bdb08c:12
    h http://wptest1.local/wp-includes/js/dist/compose.min.js?ver=6284a4846a73f9c3e3ff2d7bd0b47be7:2
    ce http://wptest1.local/wp-includes/js/dist/compose.min.js?ver=6284a4846a73f9c3e3ff2d7bd0b47be7:2
    T http://wptest1.local/wp-includes/js/dist/compose.min.js?ver=6284a4846a73f9c3e3ff2d7bd0b47be7:2
    P http://wptest1.local/wp-includes/js/dist/compose.min.js?ver=6284a4846a73f9c3e3ff2d7bd0b47be7:2
    A http://wptest1.local/wp-includes/js/dist/compose.min.js?ver=6284a4846a73f9c3e3ff2d7bd0b47be7:2
    Aj http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:161
    unstable_runWithPriority http://wptest1.local/wp-includes/js/dist/vendor/react.min.js?ver=16.13.1:25
    Da http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:60
    ab http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:154
    Te http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:146
    Pg http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:61
    unstable_runWithPriority http://wptest1.local/wp-includes/js/dist/vendor/react.min.js?ver=16.13.1:25
    Da http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:60
    Pg http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:61
    ha http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:60
    <anonymous> http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:236
    Ei http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:41
    Cb http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:41
    w http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:40
    Md http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:35
    oa http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:44
    hj http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:117
    Sh http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:152
    Th http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:152
    tj http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:152
    Te http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:146
    Pg http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:61
    unstable_runWithPriority http://wptest1.local/wp-includes/js/dist/vendor/react.min.js?ver=16.13.1:25
    Da http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:60
    Pg http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:61
    ha http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:60
    Ja http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:224
    ch http://wptest1.local/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:93
    e http://wptest1.local/wp-includes/js/dist/data.min.js?ver=7bfa3a673439e85e459d5ec92d30fdda:2
    t http://wptest1.local/wp-includes/js/dist/data.min.js?ver=7bfa3a673439e85e459d5ec92d30fdda:2
    v http://wptest1.local/wp-includes/js/dist/data.min.js?ver=7bfa3a673439e85e459d5ec92d30fdda:2
    b http://wptest1.local/wp-includes/js/dist/data.min.js?ver=7bfa3a673439e85e459d5ec92d30fdda:2
    i Redux
    A http://wptest1.local/wp-includes/js/dist/data.min.js?ver=7bfa3a673439e85e459d5ec92d30fdda:2
    L http://wptest1.local/wp-includes/js/dist/data.min.js?ver=7bfa3a673439e85e459d5ec92d30fdda:2
    dispatch http://wptest1.local/wp-includes/js/dist/data.min.js?ver=7bfa3a673439e85e459d5ec92d30fdda:2
    Redux 3
react-dom.min.js:125:24

Thanks Israel Barragan for your help with this ticket!

[torsten3d]

Same here on many installations.