Gmail OAuth login ends with blank page after "Allow" (Thunderbird 142, 115.13, 140.2 ESR – Windows 10 Pro)
I use Thunderbird to manage my personal Gmail. After changing my Google account password, I had to go through the authentication process. At first, it failed with the message: “Cookies are not enabled. Try again.” On my main PC (Windows 10 Pro), I tried several times to set up my Gmail account in Thunderbird (profile changes, uninstall/reinstall), but without success. After those attempts, Thunderbird stopped showing the “cookies” message, and every setup attempt now ends in a blank (white) page: either just before the second-factor authentication (2FA), or — less often — right after the 2FA is completed. This behavior continues even now that cookies are properly enabled. The first Thunderbird version I used was 142.0, but I also tried 115.13 and 140.2 ESR with the same result. In all cases, the process always ends with the blank page, and the account setup never completes.
Thank you in advance for your help.
தீர்வு தேர்ந்தெடுக்கப்பட்டது
Solved: After several attempts, I discovered that the issue was caused by PRTG Network Monitor installed on my PC. PRTG was intercepting HTTPS traffic locally (via localhost) and creating its own self-signed SSL certificate, which Thunderbird detected as an untrusted issuer (SEC_ERROR_UNKNOWN_ISSUER).
Once I uninstalled PRTG completely, Thunderbird connected to Gmail successfully again and everything worked normally.
Posting this in case it helps someone else facing the same authentication error after a password change or network reconfiguration.
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தீர்வு தேர்ந்தெடுக்கப்பட்டது
Solved: After several attempts, I discovered that the issue was caused by PRTG Network Monitor installed on my PC. PRTG was intercepting HTTPS traffic locally (via localhost) and creating its own self-signed SSL certificate, which Thunderbird detected as an untrusted issuer (SEC_ERROR_UNKNOWN_ISSUER).
Once I uninstalled PRTG completely, Thunderbird connected to Gmail successfully again and everything worked normally.
Posting this in case it helps someone else facing the same authentication error after a password change or network reconfiguration.
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