lets check and see what is stored inside the keystore.
You can do this by using the following command:

sudo keytool -list -keystore /var/lib/unifi/keystore

password is aircontrolenterprise

delete it using the following command:
sudo keytool -delete -alias unifi -keystore /var/lib/unifi/keystore

“openssl pkcs12 -export -in -inkey -out -passout pass:aircontrolenterprise -name unifi” or
“openssl pkcs12 -export -nodes -out -inkey -in -certfile -passout pass:aircontrolenterprise -name unifi”
then
“keytool -importkeystore -srckeystore -srcstorepass aircontrolenterprise -destkeystore /var/lib/unifi/keystore -deststorepass aircontrolenterprise -alias unifi -trustcacerts”

The left to do is to restart the Unifi controller and you are good to go!
“systemctl restart unifi”