Seeing the same.
Restarting Sonarr seems to be a workaround but I have to do it daily now. Following re-start, performing a manual index connection test is successful.
Sonarr version: 2.0.0.5344
OS: Win 8.1 Pro
Log entries:
20-9-4 22:07:38.8|Warn|Newznab|Unable to connect to indexer
[v2.0.0.5344] System.Net.WebException: The request was aborted: Could not create SSL/TLS secure channel.
at System.Net.HttpWebRequest.GetResponse()
at NzbDrone.Common.Http.Dispatchers.ManagedHttpDispatcher.GetResponse(HttpRequest request, CookieContainer cookies) in C:\BuildAgent\work\5d7581516c0ee5b3\src\NzbDrone.Common\Http\Dispatchers\ManagedHttpDispatcher.cs:line 117
at NzbDrone.Common.Http.Dispatchers.FallbackHttpDispatcher.GetResponse(HttpRequest request, CookieContainer cookies) in C:\BuildAgent\work\5d7581516c0ee5b3\src\NzbDrone.Common\Http\Dispatchers\FallbackHttpDispatcher.cs:line 53
at NzbDrone.Common.Http.HttpClient.ExecuteRequest(HttpRequest request, CookieContainer cookieContainer) in C:\BuildAgent\work\5d7581516c0ee5b3\src\NzbDrone.Common\Http\HttpClient.cs:line 121
at NzbDrone.Common.Http.HttpClient.Execute(HttpRequest request) in C:\BuildAgent\work\5d7581516c0ee5b3\src\NzbDrone.Common\Http\HttpClient.cs:line 57
at NzbDrone.Core.Indexers.HttpIndexerBase1.FetchIndexerResponse(IndexerRequest request) in C:\BuildAgent\work\5d7581516c0ee5b3\src\NzbDrone.Core\Indexers\HttpIndexerBase.cs:line 321 at NzbDrone.Core.Indexers.HttpIndexerBase
1.FetchPage(IndexerRequest request, IParseIndexerResponse parser) in C:\BuildAgent\work\5d7581516c0ee5b3\src\NzbDrone.Core\Indexers\HttpIndexerBase.cs:line 298
at NzbDrone.Core.Indexers.HttpIndexerBase`1.TestConnection() in C:\BuildAgent\work\5d7581516c0ee5b3\src\NzbDrone.Core\Indexers\HttpIndexerBase.cs:line 334
20-9-4 22:07:38.8|Warn|NzbDroneErrorPipeline|Invalid request Validation failed:
– Unable to connect to indexer, check the log for more details