Fresh install on Synology - "Object reference not set to an instance of an object" on load

Sonarr version:
Mono version (if Sonarr is not running on Windows):
OS: Synology DSM 7.01
Debug logs:

[v3.0.5.1144] System.NullReferenceException: Object reference not set to an instance of an object
at Nancy.Responses.Negotiation.DefaultResponseNegotiator+d__10.MoveNext () [0x000da] in :0
at System.Linq.Enumerable.Any[TSource] (System.Collections.Generic.IEnumerable1[T] source) [0x00015] in <b6496d2162cd48e1bb4e6753184b3d82>:0 at Nancy.Responses.Negotiation.DefaultResponseNegotiator+<GetCompatibleHeaders>d__8.MoveNext () [0x00131] in <e31b230dbd29407fadcc55713e0bbd0f>:0 at System.Collections.Generic.LargeArrayBuilder1[T].AddRange (System.Collections.Generic.IEnumerable1[T] items) [0x0003d] in <b6496d2162cd48e1bb4e6753184b3d82>:0 at System.Collections.Generic.EnumerableHelpers.ToArray[T] (System.Collections.Generic.IEnumerable1[T] source) [0x00033] in :0
at System.Linq.Enumerable.ToArray[TSource] (System.Collections.Generic.IEnumerable`1[T] source) [0x00018] in :0
at Nancy.Responses.Negotiation.DefaultResponseNegotiator.NegotiateResponse (System.Object routeResult, Nancy.NancyContext context) [0x00202] in :0
at Nancy.Routing.DefaultRouteInvoker.Invoke (Nancy.Routing.Route route, System.Threading.CancellationToken cancellationToken, Nancy.DynamicDictionary parameters, Nancy.NancyContext context) [0x0011a] in :0
at Nancy.Routing.DefaultRequestDispatcher.Dispatch (Nancy.NancyContext context, System.Threading.CancellationToken cancellationToken) [0x002b7] in :0
at Nancy.NancyEngine.InvokeRequestLifeCycle (Nancy.NancyContext context, System.Threading.CancellationToken cancellationToken, Nancy.Bootstrapper.IPipelines pipelines) [0x0011d] in :0

Description of issue:

Clean install of Sonarr via Synology Community Packages onto DSM 7.01. This also added Mono as a dependency. Loaded Sonarr up and got "Object reference not set to an instance of an object

What makes you think that error spew are debug logs?

Those are not logs and just the error is not useful. Logs should also not be posted within the post - another thing you ignored.

Please review the wiki link that you ignored that says how to get and provide logs.

You’re over 200 builds out of date. Update.

If you cannot update or sonarr cannot run then contact the SynoCommunity who creates and maintains the NAS packages for support

If your NAS supports docker it is suggested to use that. The NAS packages are poorly maintained by the SynoCommunity.