Investigation found that the Session Recording Server is running 2402 CU1, while the Session Recording Player has been upgraded to a newer version.

Starting from 2402 CU2, the product changed the communication interface between the Player and the Server. Version 2402 CU1 uses the endpoint "SessionRecordingBroker/Player.rem", whereas 2402 CU2 and later use the REST API endpoint "SessionRecordingRestApiService/api.recordingsSearch".

Because the newer Player is not compatible with the communication interface provided by a 2402 CU1 Server, search requests fail with 404: NotFound.

A version incompatibility between the upgraded Session Recording Player and the Session Recording Server. The server is still running 2402 CU1, which does not support the communication protocol required by newer Player versions.

Upgrade the Session Recording Server to 2402 CU2 or later so that it uses the new REST API and is compatible with the newer Session Recording Player.

After upgrading the Session Recording Player, users receive the error "Search for recorded session files failed. 404: NotFound." when performing a search. The issue is caused by a version mismatch between the upgraded Session Recording Player and the Session Recording Server, which is still running version 2402 CU1.