This happens at the mediaserver itself on Windows11. On my iphone and on the Android TV everything is fine. I use Google Chrome and tried it on Edge, but the error remains.

In turned debug on and did the categorie thing on two of my own libraries without any problems, than tried the Movies and Series and saw this in the debug.log (as it was my last action in Plex):

{
“type”: “ajax”,
“url”: “https://clients.plex.tv/api/subscriptions/plans?feature=remote&X-Plex-Product=Plex%20Web&X-Plex-Version=4.147.1&X-Plex-Client-Identifier=ouxasi7z45ckgmpxnrcofnp8&X-Plex-Platform=Chrome&X-Plex-Platform-Version=144.0&X-Plex-Features=external-media%2Cindirect-media%2Chub-style-list&X-Plex-Model=bundled&X-Plex-Device=Windows&X-Plex-Device-Name=Chrome&X-Plex-Device-Screen-Resolution=776x1263%2C3440x1440&X-Plex-Token=TOKEN&X-Plex-Language=nl&X-Plex-Session-Id=cd3da18a-7137-477f-8cf6-00a5407e0b68”,
“status”: 200,
“headers”: {
“Accept-Language”: “nl”,
“Accept”: “application/xml”
},
“responseLength”: 258,
“time”: “2026-01-31T07:25:21.366Z”
},
{
“type”: “log:message”,
“level”: 0,
“message”: “{\n “message”: “Request failed with status code 400”,\n “name”: “Error”,\n “stack”: “Error: Request failed with status code 400\n at e.exports (:32400/web/js/3115-3115-392610b7bb1c3beeb77e-plex-4.147.1-4ca0656.js:2:175373)\n at e.exports (:32400/web/js/3115-3115-392610b7bb1c3beeb77e-plex-4.147.1-4ca0656.js:2:177792)\n at XMLHttpRequest.y (:32400/web/js/3115-3115-392610b7bb1c3beeb77e-plex-4.147.1-4ca0656.js:2:170699)”,\n “status”: 400,\n “data”: {\n “Error”: {\n “error”: “Bad Request”,\n “message”: “Invalid value provided for x-plex-container-size!”,\n “statusCode”: 400\n }\n }\n}”,
“time”: “2026-01-31T07:25:21.513Z”
},