If you are using Firefox: click on the padlock icon -> "more information" -> "view certificate" and then on the "details" tab. If you check "certificate signatu

If you are using Firefox: click on the padlock icon -> "more information" -> "view certificate" and then on the "details" tab. If you check "certificate signature algorithm" for each of the 3 certificates, you'll see that the root certificate as well as your own one are using SHA256 but that the intermediate certificate is using SHA1. You need to bundle the right intermediate certificate which you can find, together with additional information, on https://shaaaaaaaaaaaaa.com/ https://shaaaaaaaaaaaaa.com/