I am using the SDL Template Builder 7.1 (build 7.1.0.114).

The template builder worked correctly for a long time but now I am getting the following error by every template I try to debug:

System.Web.Services.Protocols.SoapException: Type System.Runtime.Remoting.ObjRef and the types derived from it (such as System.Runtime.Remoting.ObjRef) are not permitted to be deserialized at this security level.

at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall) at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters) at Tridion.ContentManager.Templating.CompoundTemplates.DomainModel.Proxy.CompoundTemplateWebService.StartDebuggingWithItemUri(String compoundTemplateId, String compoundTemplateXml, String itemId, Boolean includeSystemLog, TraceEventType logLevel) at Tridion.ContentManager.Templating.CompoundTemplates.DomainModel.DebugObject.Start(Template template, Object debugItem, LoggingOptions loggingOptions)

What I already tried:

• I tried the 'Log on As...' option but that didn't help.

• I checked some other StackExchange posts but couldn't find the same situation.

• I added the following section to the web.config in Tridion/templating directory (after a suggestion of Nuno)

Thanks in advance!