LM Studio Will Not Load the Model: What Each Error Means

LM Studio's error messages are not always clear about what went wrong. Almost always it is capacity, and the fix is to pick a file that fits rather than to reinstall anything.

At Q4_K_M with an 8K context, computed against usable memory rather than nameplate:

• ▸8 GB card — about 7.2 GB usable. Largest model: 8B.
• ▸12 GB card — about 10.8 GB usable. Largest: 14B.
• ▸16 GB card — about 14.4 GB usable. Still 14B.
• ▸24 GB card — about 21.6 GB usable. Largest: 27B.

It loads, then immediately unloads

The weights fit but the cache does not. Lower the context length in the model's load settings before trying anything else.

Failed to load model / exit code 6 or 42

Usually out of memory dressed up as a generic failure. Check the file size against your usable memory — if the GGUF is within about 2 GB of your card's capacity, it will not fit once cache and overhead are added.

It loads but generates at a crawl

Partial GPU offload. Look at the GPU offload slider — if it is not at maximum and cannot go there, the model is too big for full residency.

Unsupported architecture or unknown model

This one is genuinely not capacity. The GGUF uses an architecture your build of llama.cpp does not know. Update LM Studio; new architectures need runtime support and a recent quant of a brand-new model often needs the newest build.

Most of this is avoidable at the download step. The rule: choose the largest quantisation whose file is at least 2 GB below your usable memory, which leaves room for the cache and runtime overhead.

Every figure here is computed the same way the calculators do it: weights are parameters times bits-per-weight divided by eight, plus a KV-cache term for your context, plus about a gigabyte of runtime overhead. Usable memory is roughly 90% of nameplate on a discrete card.