I'm having problems building the models for a v7 site using the Models Builder API and Visual Studio package. When attempting to generate the models I get the below exception:

UmbracoModelsBuilder: Starting v8.0.5 13/02/2020 11:30:11.
UmbracoModelsBuilder: UmbracoModelsBuilder failed to generate code: Exception: Response status code does not indicate success (InternalServerError)
{"Message":"An error has occurred.","ExceptionMessage":"Syntax error, ',' expected","ExceptionType":"Umbraco.ModelsBuilder.Building.CompilerException","StackTrace":"   at Umbraco.ModelsBuilder.Building.Compiler.ThrowExceptionFromDiagnostic(String path, String code, Diagnostic diagnostic) in D:\\d\\Zbu ModelsBuilder-7\\Umbraco.ModelsBuilder\\Building\\Compiler.cs:line 161\r\n   at Umbraco.ModelsBuilder.Building.Compiler.<>c__DisplayClass12_0.<GetCompilation>b__0(KeyValuePair`2 x) in D:\\d\\Zbu ModelsBuilder-7\\Umbraco.ModelsBuilder\\Building\\Compiler.cs:line 50\r\n   at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()\r\n   at System.Linq.Buffer`1..ctor(IEnumerable`1 source)\r\n   at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)\r\n   at Umbraco.ModelsBuilder.Building.Compiler.GetCompilation(String assemblyName, IDictionary`2 files, SyntaxTree[]& trees) in D:\\d\\Zbu ModelsBuilder-7\\Umbraco.ModelsBuilder\\Building\\Compiler.cs:line 46\r\n   at Umbraco.ModelsBuilder.Building.CodeParser.Parse(IDictionary`2 files, IEnumerable`1 references) in D:\\d\\Zbu ModelsBuilder-7\\Umbraco.ModelsBuilder\\Building\\CodeParser.cs:line 38\r\n   at Umbraco.ModelsBuilder.Api.ApiHelper.GetModels(String modelsNamespace, IDictionary`2 files) in D:\\d\\Zbu ModelsBuilder-7\\Umbraco.ModelsBuilder\\Api\\ApiHelper.cs:line 16\r\n   at Umbraco.ModelsBuilder.Api.ModelsBuilderApiController.GetModels(GetModelsData data) in D:\\d\\Zbu ModelsBuilder-7\\Umbraco.ModelsBuilder.Api\\ModelsBuilderApiController.cs:line 65\r\n   at lambda_method(Closure , Object , Object[] )\r\n   at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.<>c__DisplayClass10.<GetExecutor>b__9(Object instance, Object[] methodParameters)\r\n   at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.Execute(Object instance, Object[] arguments)\r\n   at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ExecuteAsync(HttpControllerContext controllerContext, IDictionary`2 arguments, CancellationToken cancellationToken)\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Web.Http.Controllers.ApiControllerActionInvoker.<InvokeActionAsyncCore>d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Web.Http.Filters.ActionFilterAttribute.<CallOnActionExecutedAsync>d__5.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Web.Http.Filters.ActionFilterAttribute.<CallOnActionExecutedAsync>d__5.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Web.Http.Filters.ActionFilterAttribute.<ExecuteActionFilterAsyncCore>d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Web.Http.Controllers.ActionFilterResult.<ExecuteAsync>d__2.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Web.Http.Filters.AuthorizationFilterAttribute.<ExecuteAuthorizationFilterAsyncCore>d__2.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.MoveNext()"}
UmbracoModelsBuilder:    at Umbraco.ModelsBuilder.Api.ApiClient.EnsureSuccess(HttpResponseMessage result)
   at Umbraco.ModelsBuilder.Api.ApiClient.GetModels(Dictionary`2 ourFiles, String modelsNamespace)
   at Umbraco.ModelsBuilder.CustomTool.CustomTool.UmbracoModelsBuilder.GenerateRaw(String wszInputFilePath, String wszDefaultNamespace, IntPtr[] rgbOutputFileContents, UInt32& pcbOutput, String& errMsg)

First of all, I'm not sure how/why it is reporting ModelsBuilder v8.0.5 because it's not installed. The version installed via Nuget is v3.0.10 which is the latest for v7, I've cleared out the bin directory and done a full rebuild to be sure and checked each package.config file.

<package id="Umbraco.ModelsBuilder" version="3.0.10" targetFramework="net461" />
<package id="Umbraco.ModelsBuilder.Api" version="3.0.10" targetFramework="net461" />

I have the following in appsettings:

<add key="Umbraco.ModelsBuilder.Enable" value="true" />
<add key="Umbraco.ModelsBuilder.ModelsMode" value="" />
<add key="Umbraco.ModelsBuilder.EnableApi" value="true" />
<add key="Umbraco.ModelsBuilder.LanguageVersion" value="CSharp6" />
<add key="Umbraco.ModelsBuilder.ModelsNamespace" value="My.Namespace.Models" />

The output window in Visual Studio offers no detail at all to help track down the issue so wondering if anyone else has had this and resolved it? The solution builds just fine but we need the models.

Any ideas?

Edit: I can change the Mode to LiveAppData and generate the models in Umbraco just fine so it looks like the tool for some reason failing.