How to fix an invalid certificate error DLG_FLAGS_SEC_CERT_CN_INVALID

Hello,

Before you do anything, we suggest you check our guide by following this link: https://ugetfix.com/ask/how-to-fix-this-site-is-not-secure-pop-up-with-an-error-code-dlg_flags_sec_cert_cn_invalid/.

The suggested fixes include clearing browser cache, installing missing certificates and disabling the "Warn about certificate address mismatch" option. Additionally, we would suggest you scan your device with anti-virus software in case malware is blocking access to the internet.

There is another, advanced method of fixing (Disabling HSTS settings) the issue on Internet Explorer, but it includes substantial modification of Windows registry, which is never recommended for regular users. Therefore, you should try downloading and installing PC repair software Reimage - it can fix various Windows-related issues automatically.

Good luck.