Thanks for your response!
Nothing to see in Event Log.
I rebooted all IAPs in the meantime. On IAP, I ran command "show ap debug airwave" and see status "Connected".
"Show log ap-debug" tells me the following:
awc_init_connection: 2550: connected to 10.xxx.xxx.xxx:443
Failed to establish SSL connection: Error code is -1:ASN parsing error, invalid input
awc_login: awc_init error
"Show log provisioning" shows me:
Airwave In progress Connecting to primary AMP server at 10.xxx.xxx.xxx...
Airwave In progress Connected with primary AMP server 10.xxx.xxx.xxx, logging in...
Airwave Debug Logging out of AMP server primary
Airwave Failed Error establishing SSL connection to AMP server at 10.xxx.xxx.xxx: ASN parsing error, invalid input
Airwave Failed Login aborted due to incomplete response from primary AMP server