APM issue errorcode=19

hi,
For lagacy purpose, I need to create an APM on my VS.

I don't understand why but applying any Access Policy on my VS result on an errocode=19 "access denied"

The VS is a basic HTTP Virtual server 

IP xxx.xxx.xx.xx

Listen adress 80

Pool redirecting to a single host

Protocol tcp

protocol client & server tcp

HTTP Profile client & server http
VLAN & SNATPOOL Defined

No Irule, Nor perstence profile

When i don't enable the APM the VS is working as expected

I've reduced The Access Policy to the simpliest,

Start --> Allow

And set the SSO Auth Domains - Cookie Options  to HTTP Only

Any help would be appreciated