Failed To Start Playback Netsdk Returns Error Smart Pss Exclusive _hot_ -

The "Failed to start playback: NETSDK returns error" with "Smart PSS exclusive" symptoms indicates the playback request from Smart PSS (or SDK client using the NETSDK/Hikvision SDK) is being refused because the device or SDK session state enforces exclusive access—another client or SDK instance is holding the decoder/stream or the device's resources. Root causes include concurrent session limits, exclusive SDK mode, account/permission issues, incompatible stream types, channel/codec mismatch, or firmware/SDK bugs. The remainder of this report explains likely causes, diagnostic steps, logs and commands to collect, reproducible test cases, mitigation and long-term fixes, and a prioritized action plan.