After installing the Dynamic Web TWAIN (PKG) on your Mac OS X and refreshing your scan page, you are asked to download and install the PKG repeatedly.
You are visiting the scan page via HTTPS.
Dynamsoft uses an SSL self-signed certification for HTTPS websites. However, Safari v7+ failed to verify the certification. This is a known issue in Safari v7+ only.
Please follow the steps below to resolve the error:
1. Visit https://127.0.0.1:18619, and you will see the message below:
2. Click on "Show Certificate" and you will see -
3. Check the option "Always trust "127.0.0.1" when connecting to "127.0.0.1" and click on "Continue"
4. Your login credential will be required to apply the change. Please input your password and click on "Update Settings"
5. When you see the following page, it means the change has been made successfully. Go back to your scan page, and it should be without errors now.
If the above solution doesn't work, please use Keychain Access > System and search for 127.0.0.1. Select always trust for this certificate.