Problem saving the code / Failed to save [file]: Unknown Save Error - Sentry exception

🐛 bug report

Preflight Checklist

• I have read the
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• I agree to follow the
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  that this project adheres to.
• I have searched the issue tracker for an issue that matches the one I want
  to file, without success.

Description of the problem

Upon saving a file, I get two notification on the bottom right:

• There was a problem with saving the code, please try again
• Failed to save 'DialogueParser.js': Unknown Save Error

Seems to be a problem with sentry, the network tab shows a failed request to sentry.io on save, with the response carrying the exception "Non-Error exception captured with keys: reason"

On top of that, the developer console displays the following errors on attempting to save:

• "The operation's base length must be equal to the string's length. String length: 0, base length: 1193"
• POST https://sentry.io/api/2071895/store/?sentry_key=f595bc90ce3646c4a9d76a8d3b84b403&sentry_version=7 net::ERR_BLOCKED_BY_CLIENT

This only happens in one file, the rest of the files in the sandbox work and save fine.

How has this issue affected you? What are you trying to accomplish?

The file is forever marked in an "unsaved" state. Worth mentioning that even with the errors above, the file seems to save fine for my user as opening the sandbox in a different browser / incognito mode shows the latest edits, however when accessing the sandbox via a public link the file appears empty.

To Reproduce

To be honest, I have no idea. it just started happening out of the blue, for just one file in one sandbox.

Your Environment

The report identifies DialogueParser.js and browser console/network errors, but no implementation file, test, or entry point. Start by reproducing the save failure and tracing the save request and Sentry exception; done means the file saves without remaining unsaved or appearing empty through a public link.