**Root Cause:**
Insufficient GPU VRAM. The Key-Value (KV) cache size scales linearly with the context length. A context length of 262,144 tokens requires gigabytes of VRAM even for small models, but the GPU only has 1024 MiB (1 GiB) of free memory available.

**Next Two Actions:**
1. **Reduce the context length:** Lower the `--ctx-size` (or `--context-length`) parameter to a value that fits within the available GPU memory (e.g., 4096 or 8192).
2. **Offload to CPU or use a smaller model:** If the 262k context is mandatory, offload the KV cache to the CPU by setting `--n-gpu-layers 0` and ensure sufficient system RAM is available. Alternatively, use a smaller model or a lower quantization (e.g., Q4_K_M instead of Q8_0) to reduce the per-token memory footprint.