"Sorry! Something went wrong." error every time I open a shared Numbers document in a browser

HELP! I use Numbers for creating project tracking documents at work, and suddenly none of them work anymore. I originally created them in Numbers on a Mac, and then I shared them online. I only open them in a web browser (or as a webpage tab within Microsoft Teams). They are set to be shared such that anyone with the link should be able to open and view them. Most of the users who are editing them are not Mac users and are accessing them on Windows.

We have been using these spreadsheets for YEARS with no issue, but they all appear to have stopped working this week. I've tried opening them via the link and by signing into iCloud in a web browser and using Numbers online to open the files. No matter what I do, this is the message I get:

The text in the "Details" section is as follows:

FetchDocument

Server reply error when fetching document: Unexpected server error when fetching document

== Environment ==

URL: https://www.icloud.com/numbers/0jo8FxXO2IAWqYvTbVUVw7iCA#2021-11-16%2C17_-_Ground_Transportation_Engine_and_Power_Train_copy

UA String: Mozilla/5.0 (Macintosh; Intel Mac OS X 12_2_1) AppleWebKit/537.36 (KHTML, like Gecko) Teams/1.5.00.4683 Chrome/85.0.4183.121 Electron/10.4.7 Safari/537.36

Date: Sun, 06 Mar 2022 05:15:34 GMT

Build environment: production

Asset URL: https://p102-iwres.icloud.com:443/asset/

Res URL: https://p102-iwres.icloud.com:443/iwmb/

MBWS URL: https://p102-iwmb5.icloud.com:443/iwmb/

SCMP URL: https://p102-iwmb5.icloud.com:443/scmp/

iCloud environment: PROD

DS_ID: User not logged in

== Inspectee ==

== OT ==

== Mailbox ==

Mailbox Session: A8BFAEA6-0B3D-4334-BE41-AB7A73C7ABFC

Incoming: Normal; Outgoing: Suspended

Command Deque (rsvp | sendPending): [ | ]

20220306 00:15:22.126 [00:15:22.126-5 GSN.AbstractMailboxController] Network-related configs:

20220306 00:15:22.126 [00:15:22.126-5 GSN.AbstractMailboxController] - network.connectionIdleTimeout = 20000

20220306 00:15:22.126 [00:15:22.126-5 GSN.AbstractMailboxController] - network.connectionRetryInterval = 1000

20220306 00:15:22.126 [00:15:22.126-5 GSN.AbstractMailboxController] - network.connectionRetryMaxBackoff = 4

20220306 00:15:22.126 [00:15:22.126-5 GSN.AbstractMailboxController] - network.reInitDelay = 1000

20220306 00:15:22.126 [00:15:22.126-5 GSN.AbstractMailboxController] - network.reInitMaxBackoff = 3

20220306 00:15:22.126 [00:15:22.126-5 GSN.AbstractMailboxController] - network.reInitLimit = 10

20220306 00:15:22.126 [00:15:22.126-5 GSN.AbstractMailboxController] - network.persistentDisconnectionTimeout = 20000

20220306 00:15:22.126 [00:15:22.126-5 GSN.AbstractMailboxController] - network.commandResponseTimeout = 300000

20220306 00:15:22.126 [00:15:22.126-5 GSN.AbstractMailboxController] - network.offlineWarningTimeout = 10000

20220306 00:15:22.126 [00:15:22.126-5 GSN.AbstractMailboxController] Mailbox initiated.

20220306 00:15:22.127 [00:15:22.127-5 GSN.FetchControllerPasswordConsumer] setPasswordReady: false

20220306 00:15:22.127 [00:15:22.127-5 GSN.MailboxControllerPasswordConsumer] setPasswordReady: false

20220306 00:15:22.128 [00:15:22.128-5 GSN.AbstractPasswordController] Entered state: GSN.VerifyPasswordForFetch:76

20220306 00:15:22.128 [00:15:22.128-5 GSN.AbstractPasswordController] setPasswordReady: true

20220306 00:15:22.128 [00:15:22.128-5 GSN.FetchControllerPasswordConsumer] setPasswordReady: true

== Network ==

== Playback ==

== Replay Script ==

Any ideas on what's going on? This has been an issue for several days now and I have no idea what's happening.