This issue is not limited to a single version of KEPServerEX. According to official PTC support documentation, the problem has been observed across a wide range of versions on several Windows platforms.

Locate the Kepware .exe installer file on an internet-connected machine. Right-click the file and select . Switch to the Digital Signatures tab. Select the signature name from the list and click Details .

Method 1: Apply Windows Updates (Best for Connected Systems)

By following the solutions in this guide—updating Windows root certificates, manually importing the missing CAs, or using advanced bypass switches—you will restore the ability to install Kepware on any industrial PC.