Invalid property name in input[303].arguments after attaching a large JSON file (conversation becomes permanently unusable)

What version of the Codex App are you using (From “About Codex” dialog)?

Version 26.721.41059

What subscription do you have?

Plus

What platform is your computer?

_No response_

What issue are you seeing?

After attaching a large JSON file, this conversation became permanently unusable.

Every new message returns the same error:

Invalid property name in 'input[303].arguments'...

I removed the JSON file, moved it to another location, restarted the app, and even sent unrelated prompts, but the error still appears.

It seems the conversation has cached a corrupted internal state. Is there any way to reset or recover the conversation without starting a new one?

Error: Invalid property name in 'input[303].arguments': ']=l...;?>' is too long. Expected a string with maximum length 256, but got a string with length 939 instead.

What steps can reproduce the bug?

Feedback ID: 019e505c-74f6-74e3-ade5-3c2bf8ce735e

What is the expected behavior?

_No response_

Additional information

_No response_