Table editor error: Cannot read properties of null (reading 'length') persists on 2026.2.0-latest

Bug
,
1

Continuing the discussion from Unable to edit tables:

Hi all, following up with more concrete data.

I can confirm this issue is still reproducible on latest.

Environment

  • Discourse: v2026.2.0-latest +209 (after full rebuild)
  • Previously also observed on: v2026.2.0-latest +165
  • Browser: Chrome

What I’ve tried

  • Full rebuild / update to +209
  • Hard refresh
  • Reproduced in Safe Mode with:
    • themes disabled
    • unofficial client-side customisations disabled
    • all client-side plugin customisations disabled

Result

  • Editing a table and clicking the blue Save button consistently throws:
Uncaught TypeError: Cannot read properties of null (reading 'length')
  at buildUpdatedPost (spreadsheet-editor.gjs:261)
  at updateTable
  at insertTable
  • UI does not save or update the post.
  • Same behaviour occurs in Safe Mode.
Screenshots attached showing the console error and Safe Mode reproduction.

not safe mode

image
image1407×360 125 KB

safe mode

image
image1340×637 181 KB

2
Column 1 Column 2 Column 3 Column 4 Column 5 Column 6 Column 7 Column 8 Column 9 Column 10
Row 1, Cell 1 Row 1, Cell 2 Row 1, Cell 33 Row 1, Cell 4 Row 1, Cell 5 Row 1, Cell 6 Row 1, Cell 7 Row 1, Cell 8 Row 1, Cell 9 Row 1, Cell 10
Row 2, Cell 1 Row 2, Cell 2 Row 2, Cell 3 Row 2, Cell 4 Row 2, Cell 5 Row 2, Cell 6 Row 2, Cell 7 Row 2, Cell 8 Row 2, Cell 9 Row 2, Cell 10
Row 3, Cell 1 Row 3, Cell 2 Row 3, Cell 3 Row 3, Cell 4 Row 3, Cell 5 Row 3, Cell 6 Row 3, Cell 7 Row 3, Cell 8 Row 3, Cell 9 Row 3, Cell 10
3

Not reproducible here (trivially)

Is it something about your particular table? Can you include full markdown?

4 
Material | $\varepsilon_r$
-------- | --------------
Dry air  | 1.0006
Paper    | 3
Diamond  | 5
Silicon  | 12
HfO $_2$  (Hf = Hafnium) | 25
H $_2$ O   | 80
BaTiO $_3$ (Barium Titan - useful for keeping its polarisation) | $\sim 4000$
Material \varepsilon_r
Dry air 1.0006
Paper 3
Diamond 5
Silicon 12
HfO _2 (Hf = Hafnium) 25
H _2 O 80
BaTiO _3 (Barium Titan - useful for keeping its polarisation) \sim 4000
לייק 1
6

OK this is fixed per:

We were leaning on regex to find tables and it did not like this table format.

The change is to lean on markdown parsing which is much more robust.

לייק 1
7

I’m currently on 2026.2.0-latest (8125ffa60a).

The issue still reproduces there, including in Safe Mode and PWA.

Looks like this commit predates PR #37658 - happy to retest once latest advances past the merge.