still not quite right
I found the line on pp_confirm.php
changed
$WA_PP_ECO_GetResult = WA_PP_ECO_Get_Post("liveapiusername", "liveapipassword", "liveapisignature", false);
to
$WA_PP_ECO_GetResult = WA_PP_ECO_Get_Post("sandboxapiusername", "sandboxapipassword", "sandboxapisignature", true);
but still get the error
No worries, I'll can wait until the update and try again