Getting large Alert volume now, e.g. job edit Source screen gets 12 looking like:
Originally seen on a different job where it seemed like any file got HTTP asking:
Profiling log shows the likely info of that particular 500 Internal Server Error:
2026-05-11 15:55:57 -04 - [Error-Duplicati.WebserverCore.DuplicatiWebserver-UnhandledException]: Unhandled exception in webserver request to /api/v1/filesystem
System.Exception: Failed to process the path: The parameter is incorrect. : '\\?\C:\backup source\C.txt'.
---> System.IO.IOException: The parameter is incorrect. : '\\?\C:\backup source\C.txt'.
at System.IO.Enumeration.FileSystemEnumerator`1.MoveNext()
at System.Linq.Enumerable.IEnumerableSelectIterator`2.ToArray()
at System.Linq.Enumerable.OrderedIterator`2.MoveNext()
at Duplicati.WebserverCore.Endpoints.V1.Filesystem.ListFolderAsNodes(String entrypath, Boolean skipFiles, Boolean showHidden)+MoveNext()
at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
at Duplicati.WebserverCore.Endpoints.V1.Filesystem.Execute(String path, Boolean onlyFolders, Boolean showHidden)
--- End of inner exception stack trace ---
at Duplicati.WebserverCore.Endpoints.V1.Filesystem.Execute(String path, Boolean onlyFolders, Boolean showHidden)
at lambda_method241(Closure, EndpointFilterInvocationContext)
at Duplicati.WebserverCore.Middlewares.HostnameFilter.InvokeAsync(EndpointFilterInvocationContext context, EndpointFilterDelegate next)
at Duplicati.WebserverCore.Middlewares.LanguageFilter.InvokeAsync(EndpointFilterInvocationContext context, EndpointFilterDelegate next)
at Microsoft.AspNetCore.Http.RequestDelegateFactory.<ExecuteValueTaskOfObject>g__ExecuteAwaited|130_0(ValueTask`1 valueTask, HttpContext httpContext, JsonTypeInfo`1 jsonTypeInfo)
at Microsoft.AspNetCore.Http.RequestDelegateFactory.<>c__DisplayClass102_2.<<HandleRequestBodyAndCompileRequestDelegateForJson>b__2>d.MoveNext()
--- End of stack trace from previous location ---
at Duplicati.WebserverCore.Middlewares.WebsocketExtensions.<>c__DisplayClass0_0.<<UseNotifications>b__0>d.MoveNext()
--- End of stack trace from previous location ---
at Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddlewareImpl.<Invoke>g__Awaited|10_0(ExceptionHandlerMiddlewareImpl middleware, HttpContext context, Task task)
2.3.0.101 had a different 500 problem (which I think was extra slash on folders).