I have recently starting getting these errors when casting from Android to Chromecast Ultra. It causes not stop buffering, the only fix I have found so far is to restart the plex server application or reboot the server.
Looking around on the Internet and it has something to do with a poor CORs policy implementation and it looks like the Plex server is dumping the requests
OS#: Ubuntu 18.04.6 LTS
Server Version#: 1.27.1.5916
Player Version#: 9.4.0.33297
Jun 27, 2022 00:55:54.195 [0x7f20c5ae7b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:55:57.176 [0x7f20c6341b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:55:57.724 [0x7f20c79a1b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:55:59.384 [0x7f20c5ae7b38] Warning — [Chromecast] [Player] Buffering detected, last position change was 507ms ago
Jun 27, 2022 00:55:59.575 [0x7f20c6341b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:06.481 [0x7f20c6468b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:07.141 [0x7f20c79a1b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:07.900 [0x7f20c6468b38] Warning — [Chromecast] [Player] Buffering detected, last position change was 520ms ago
Jun 27, 2022 00:56:08.051 [0x7f20c6341b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:12.272 [0x7f20c5ae7b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:14.058 [0x7f20c79a1b38] Warning — [Chromecast] [Player] Buffering detected, last position change was 515ms ago
Jun 27, 2022 00:56:14.063 [0x7f20c6468b38] Warning — QueryParser: Invalid field ‘libraryHubsOnly’ found, ignoring.
Jun 27, 2022 00:56:14.065 [0x7f20c6468b38] Warning — QueryParser: Invalid field ‘libraryHubsOnly’ found, ignoring.
Jun 27, 2022 00:56:14.066 [0x7f20c6468b38] Warning — QueryParser: Invalid field ‘libraryHubsOnly’ found, ignoring.
Jun 27, 2022 00:56:14.068 [0x7f20c6468b38] Warning — QueryParser: Invalid field ‘libraryHubsOnly’ found, ignoring.
Jun 27, 2022 00:56:14.070 [0x7f20c6468b38] Warning — QueryParser: Invalid field ‘libraryHubsOnly’ found, ignoring.
Jun 27, 2022 00:56:14.290 [0x7f20c6341b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:17.376 [0x7f20c79a1b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:20.665 [0x7f20c6468b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:21.852 [0x7f20c6341b38] Error — Unknown metadata type: folder
Jun 27, 2022 00:56:22.302 [0x7f20c79a1b38] Warning — [Chromecast] [Player] Buffering detected, last position change was 520ms ago
Jun 27, 2022 00:56:22.371 [0x7f20c6468b38] Error — Unknown metadata type: folder
Jun 27, 2022 00:56:22.490 [0x7f20c79a1b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:22.591 [0x7f20c6468b38] Warning — QueryParser: Invalid field ‘IncludeExternalMedia’ found, ignoring.
Jun 27, 2022 00:56:22.891 [0x7f20c6468b38] Error — Unknown metadata type: folder
Jun 27, 2022 00:56:27.215 [0x7f20c6341b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:29.134 [0x7f20c6468b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:30.630 [0x7f20c5ae7b38] Warning — [Chromecast] [Player] Buffering detected, last position change was 510ms ago
Jun 27, 2022 00:56:30.829 [0x7f20c6468b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:32.583 [0x7f20c6341b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:34.298 [0x7f20c6341b38] Warning — [Chromecast] [Player] Buffering detected, last position change was 518ms ago
Jun 27, 2022 00:56:34.520 [0x7f20c5ae7b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:37.495 [0x7f20c6341b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:40.324 [0x7f20c5ae7b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:41.898 [0x7f20c6468b38] Warning — [Chromecast] [Player] Buffering detected, last position change was 520ms ago
Jun 27, 2022 00:56:42.118 [0x7f20c79a1b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:45.099 [0x7f20c5ae7b38] Error — Unknown metadata type: folder
Jun 27, 2022 00:56:45.101 [0x7f20c6341b38] Warning — QueryParser: Invalid field ‘IncludeExternalMedia’ found, ignoring.
Jun 27, 2022 00:56:45.432 [0x7f20c79a1b38] Warning — QueryParser: Invalid field ‘IncludeExternalMedia’ found, ignoring.
Jun 27, 2022 00:56:45.457 [0x7f20c6341b38] Error — Unknown metadata type: folder
Jun 27, 2022 00:56:45.733 [0x7f20c5ae7b38] Error — Unknown metadata type: folder
Jun 27, 2022 00:56:46.137 [0x7f20c5ae7b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:47.117 [0x7f20c79a1b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:47.627 [0x7f20c6341b38] Warning — [Chromecast] [Player] Buffering detected, last position change was 520ms ago
Jun 27, 2022 00:56:47.839 [0x7f20c5ae7b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:54.727 [0x7f20c79a1b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:55.980 [0x7f20c5ae7b38] Warning — [Chromecast] [Player] Buffering detected, last position change was 510ms ago
Jun 27, 2022 00:56:56.115 [0x7f20c6468b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:56:57.307 [0x7f20c6341b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:57:00.118 [0x7f20c79a1b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:57:01.821 [0x7f20c5ae7b38] Warning — [Chromecast] [Player] Buffering detected, last position change was 501ms ago
Jun 27, 2022 00:57:02.008 [0x7f20c6468b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:57:07.210 [0x7f20c5ae7b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:57:12.175 [0x7f20c6468b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:57:13.874 [0x7f20c79a1b38] Warning — [Chromecast] [Player] Buffering detected, last position change was 512ms ago
Jun 27, 2022 00:57:14.097 [0x7f20c6341b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:57:17.164 [0x7f20c6341b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
Jun 27, 2022 00:57:17.280 [0x7f20c5ae7b38] Warning — [Chromecast] Did not move header “accept” to query string. This can result in an unnecessary OPTIONS preflight request.
