Really sorry everybody, have found the answer myself. It seems that
for some reason this one function cannot accept literals,

e.g.:
ISC_License_Remove('key')
cause an AV, whereas:

var pKey: array[0..3] of char;
begin
pKey:='key';
ISC_License_Remove(pKey);
end;

succeeds. hopefully worth knowing for somebody apart from me - hope I
haven't wasted anyones time,
Stuart Hunt

--- In firebird-support@yahoogroups.com, "stuartideagen"
<stuartideagen@y...> wrote:

>
> All,
> first of all thankyou very much for your help with my last

question.

> I can now check, show and add licences no problems to IB 7.1.
> However, I still have one small problem. Any attempt to call
> ISC_License_Remove results in an access violation in iblicense.dll.
> I'm calling it from a Delphi application, and have defined it as
> follows:
>
> ISC_License_Remove: function (cert_key: PChar): Integer; stdcall;
>
> calling it with either the certificate ID or key doesn't make any
> difference, I still get an access violation. The other functions,
> that I have defined in a similar manner (with an extra parameter as
> specified in the API guide) all seem ok.
> My question is, has anyone had any success with this function

and/or

> got any idea what I'm doing wrong. Any help would be most

gratefully

> received,
> Stuart Hunt,
> Technical Leader,
> IdeaGen Software Limited