extension could not be loaded because it was not properly signed

[wasimm88225959]

I'm trying to sign the extension but I still get the same error

"extension could not be loaded because it was not properly signed"

I'm using the mac with ZXPSignCmd

and photoshop cc release  19.1.3

[Trevor:]

post the code you are using to sign it

[wasimm88225959]

/Users/wassimo/Desktop/plugins/ZXPSignCmd -sign /Users/wassimo/Desktop/plugins/com.flat.arbfonts /Users/wassimo/Desktop/plugins/singing/com.flat.arbfonts.zxp /Users/wassimo/Desktop/plugins/MyCert.p12 password

[Trevor:]

Verify the sign as per described Getting-Started-guides/Package Distribute Install at master · Adobe-CEP/Getting-Started-guides · Git...

[wasimm88225959]

Error - Certificate is expired or not yet valid. Please check certificate validity.

cert command line

/Users/wassimo/Desktop/plugins/ZXPSignCmd -selfSignedCert US NY Arbfonts ArbfontsPlus password /Users/wassimo/Desktop/plugins/MyCert.p12

[wasimm88225959]

i did it right but i still get the same error!