Kaspersky Web Console - Step "Verify plug-in signature" failed

[RCBElectro]

After attempting to update from Web console → Console settings → Plug-ins, version 11.3.0.773, this message appears.

For the KSC, it was necessary to whitelist some addresses to facilitate updates, but in this case our router does not catch any warnings.

[alexcad]

Try to download and install the plugin manually
https://support.kaspersky.com/9333#block9

[RCBElectro]

Try to download and install the plugin manually
https://support.kaspersky.com/9333#block9

Indeed, I tried this, and the same symptoms occur like in the picture. Step "Verify plug-in signature" failed