Hi,
In general, that error means the "The User does not have 'ontapi' application permissions to access storage systems".
Step 1 : I am guessing this is already in place ?
::> security login role create -vserver cluster -role network-readonly -cmddirname "network interface" –access readonly
[The AV connector will connect to the cluster Mgmt interface to read out the LIFs that are active whithin the Storage Virtual Machine (SVM)]
Step 2 : Is the user given 'ontap' api access ?
cluster1::> security login create -vserver cluster1 -username <avconnect_user> -application ontapi -authmethod password
Also, could you ensure the prerequisite & best practices are followed as per this TR:
https://www.netapp.com/us/media/tr-4312.pdf
Page 17 & 18: Antivirus connector
Page 26: Add Privileged Users to Scanner Pool
Page 30: General best practices
Thanks!