Calling Web Services from a Web Form throws CAS violation

[juchytil]

We created a C# Windows forms application and put the .EXE on our web server.

We can download the executable from the web server to a desktop and it will
display OK. When we click a button that causes the executable to call a web
service on the same web server, we get the following code access security
violation.

-------------- begin violation -------------------------------------------
Could not talk to the web server. Error = 'System.Invalid OperationExcept ion:
There is an error in XML document (1, 269). --->
System.Security .SecurityExcept ion: Security error.

at
Microsoft.Xml.S erialization.Ge neratedAssembly .XmlSerializati onReader1.Read2 _ReturnDS(Boole an isNullable, Boolean checkType)

at
Microsoft.Xml.S erialization.Ge neratedAssembly .XmlSerializati onReader1.Read9 _StorlibReadRes ponse()

The granted set of the failing assembly was:
<PermissionSe t class="System.S ecurity.Permiss ionSet"
version="1">

<IPermission class="System.S ecurity.Permiss ions.FileDialog Permission,
mscorlib, Version=1.0.500 0.0, Culture=neutral ,
PublicKeyToken= b77a5c561934e08 9"
version="1"/>

<IPermission
class="System.S ecurity.Permiss ions.IsolatedSt orageFilePermis sion, mscorlib,
Version=1.0.500 0.0, Culture=neutral , PublicKeyToken= b77a5c561934e08 9"
version="1"
Allowed="None"/>

<IPermission class="System.S ecurity.Permiss ions.SecurityPe rmission,
mscorlib, Version=1.0.500 0.0, Culture=neutral ,
PublicKeyToken= b77a5c561934e08 9"
version="1"
Flags="Executio n"/>

<IPermission class="System.S ecurity.Permiss ions.UIPermissi on, mscorlib,
Version=1.0.500 0.0, Culture=neutral , PublicKeyToken= b77a5c561934e08 9"
version="1"
Window="SafeTop LevelWindows"/>

<IPermission class="System.N et.DnsPermissio n, System, Version=1.0.500 0.0,
Culture=neutral , PublicKeyToken= b77a5c561934e08 9"
version="1"/>

<IPermission class="System.D rawing.Printing .PrintingPermis sion,
System.Drawing, Version=1.0.500 0.0, Culture=neutral ,
PublicKeyToken= b03f5f7f11d50a3 a"
version="1"
Level="NoPrinti ng"/>

<IPermission class="System.D iagnostics.Perf ormanceCounterP ermission,
System, Version=1.0.500 0.0, Culture=neutral , PublicKeyToken= b77a5c561934e08 9"
version="1"/>

<IPermission class="System.S ecurity.Permiss ions.UrlIdentit yPermission,
mscorlib, Version=1.0.500 0.0, Culture=neutral ,
PublicKeyToken= b77a5c561934e08 9"
version="1"
Url="file://C:/winnt/assembly/gac/system/1.0.5000.0__b77 a5c561934e089/system.dll"/>

<IPermission class="System.S ecurity.Permiss ions.ZoneIdenti tyPermission,
mscorlib, Version=1.0.500 0.0, Culture=neutral ,
PublicKeyToken= b77a5c561934e08 9"
version="1"
Zone="MyCompute r"/>

</PermissionSet>

--- End of inner exception stack trace ---

at System.Xml.Seri alization.XmlSe rializer.Deseri alize(XmlReader
xmlReader, String encodingStyle)
at System.Xml.Seri alization.XmlSe rializer.Deseri alize(XmlReader xmlReader)
at
System.Web.Serv ices.Protocols. SoapHttpClientP rotocol.ReadRes ponse(SoapClien tMessage
message, WebResponse response, Stream responseStream, Boolean asyncCall)
at System.Web.Serv ices.Protocols. SoapHttpClientP rotocol.Invoke( String
methodName, Object[] parameters)
at BackIssue.com.k cc.cad.Service. StorlibRead(Str ing wildcard)
at BackIssue.FormM ain.searchForWi ldcard()'

---------------- end violation -------------------------------------------

What do I need to do to get past this violation?

Joe