restarted Rock, and now /api/docs/index produces the following exception

500 : {"Message":"An error has occurred.","ExceptionMessage":"Collection was modified; enumeration operation may not execute.","ExceptionType":"System.InvalidOperationException","StackTrace":" at System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource resource)\r\n at System.Collections.Generic.List`1.Enumerator.MoveNextRare()\r\n at System.Linq.Enumerable.<OfTypeIterator>d__95`1.MoveNext()\r\n at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()\r\n at System.Web.Http.Description.ApiExplorer.<FlattenRoutes>d__2.MoveNext()\r\n at System.Web.Http.Description.ApiExplorer.InitializeApiDescriptions()\r\n at System.Lazy`1.CreateValue()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Lazy`1.get_Value()\r\n at Swashbuckle.Swagger.SwaggerGenerator.GetApiDescriptionsFor(String apiVersion)\r\n at Swashbuckle.Swagger.SwaggerGenerator.GetSwagger(String rootUrl, String apiVersion)\r\n at Swashbuckle.Application.SwaggerDocsHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)\r\n at System.Net.Http.HttpMessageInvoker.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)\r\n at System.Web.Http.Dispatcher.HttpRoutingDispatcher.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)\r\n at System.Net.Http.DelegatingHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)\r\n at System.Web.Http.Cors.CorsMessageHandler.<SendAsync>d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.HttpServer.<SendAsync>d__0.MoveNext()"} https://rock.chaseoaks.org:443/api/doc/v1