The spreadsheet attached to that issue opens and saves.

Redmine keeps a great deal of a company's working knowledge as attachments, and has no way to open them. Our plugin gives it one: Redmine becomes a WOPI host, the file goes to SumSheet or SumDoc, and the edit comes back as a new attachment. Measured on Redmine 6 — the current major, which the existing alternative does not support.

What was measured

The round	A macro workbook and a document with five pictures: opened from an issue, edited, saved back. VBA byte for byte, pictures byte for byte.
The refusals	Unsigned and forged requests, corrupted tokens, wrong paths — refused.
Version	Redmine 6. Worth checking before you compare: the office plugin already in the directory declares support only for Redmine 4.2 and 5.0, and its last release was in March 2024.
What this does not say	The fixture workbook these rounds used asks Microsoft Excel to repair it on its own — so no silent-Excel claim here. See Nextcloud and Seafile.

Setting it up

# the editors, behind your TLS address
git clone https://github.com/SumOfficeApp/sumoffice-docker && cd sumoffice-docker/nextcloud
cp env.example .env    # PUBLIC_URL=https://office.example.com
docker compose up -d

# the plugin: sumoffice-docker, branch integrations, folder integrations/redmine
# copy into plugins/, run the migration, restart Redmine, set the editor address

Evaluation is free with no time limit; production is the per-application license. The other systems we measured →

Then

Check my Excel file — what your workbooks rely on.
Tell us your Redmine version — 6 is measured.