Error during Conversation, randomly happening

Google Antigravity
1

During my Coding-Session this error ocurres randomly, really frustratin as a AI Ultra User - please fix that ASAP

Trajectory ID: 6b109ada-e0c1-…
Error: HTTP 400 Bad Request
Sherlog:
TraceID: 0xcab6f7f353621c01
Headers: {“Alt-Svc”:[“h3=“:443”; ma=2592000,h3-29=“:443”; ma=2592000”],“Content-Length”:[“282”],“Content-Type”:[“text/event-stream”],“Date”:[“Thu, 19 Feb 2026 07:38:53 GMT”],“Server”:[“ESF”],“Server-Timing”:[“gfet4t7; dur=795”],“Vary”:[“Origin”,“X-Origin”,“Referer”],“X-Cloudaicompanion-Trace-Id”:[“cab6f7f353621c01”],“X-Content-Type-Options”:[“nosniff”],“X-Frame-Options”:[“SAMEORIGIN”],“X-Xss-Protection”:[“0”]}

{
“error”: {
“code”: 400,
“message”: “{“type”:“error”,“error”:{“type”:“invalid_request_error”,“message”:“messages.7.content.0.thinking.signature: Field required”},“request_id”:“req_vrtx_011CYH3gbXrVANsZUpD7EG5i”}”,
“status”: “INVALID_ARGUMENT”
}
}

2

Hi @Julian_Kirchner
Welcome to the Google AI Forum!!

A persistent 400 Bad Request error during the browser’s request headers (specifically the cookies) have become too large or corrupted for the authentication server to process. Please try the following steps:

  • Clear Cookies and Cache specifically for google.com and accounts.google.com in your default browser.

  • If you are using a strict VPN or privacy extensions (like ad-blockers) in your browser, they may be stripping required headers.

  • Please let us know if clearing the browser data resolves the issue for you.

Thank you!