Recaptcha BROWSER_ERROR

Question

Some days ago we have upgraded to Recaptcha Enterprise.
It seems that the only support channel is here on stackoverflow

What mean BROWSER_ERROR in invalidReason?

in the official doc

it's not specified

{
"name": "projects/xxxxxxxxxxxxxxxxxxxxxxx",
"event": {
"token": "xxxxxxx",
"siteKey": "XXXXXXXXXXXXXXXXXXXXXX",
"userAgent": "Mozilla/5.0 (Linux; Android 10; Redmi Note 8T) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.105 Mobile Safari/537.36",
"userIpAddress": "XXX.XXX.XXX.XXX",
"expectedAction": "login"
},
"score": 0,
"tokenProperties": {
"valid": false,
"invalidReason": "BROWSER_ERROR",
"hostname": "",
"action": ""
},
"reasons": []
}

Answer 1

I was experiencing this same error and realised the domain wasn't whitelisted in the reCAPTCHA Enterprise console, which can be accessed here.

After adding the domain, the BROWSER_ERROR error went away.

Answer 2

I ensured I whitelisted both the backend and the frontend URLs in case they were different; which was my case. You can whitelist here

Answer 3

The non-beta (v1) version of that page gives this definition:

BROWSER_ERROR - A retriable error (such as network failure) occurred on the browser. Could easily be simulated by an attacker.

(I see the v1beta1 link provided by the OP also contains this definition now, so it may have been updated in the interim.)