Local Ai
Ollama broken on Apple M5 + macOS 26 — Metal shader crash on every model (500 error)
Ollama consistently fails to run any model on Apple M5 hardware running macOS 26, with the Metal backend failing to initialize and the runner process terminating with a 500 Internal Server Error. The
Ollama consistently fails to run any model on Apple M5 hardware running macOS 26, with the Metal backend failing to initialize and the runner process terminating with a 500 Internal Server Error. The root cause is a type contract mismatch introduced in macOS 26's Metal 4 framework, where Ollama's embedded Metal shaders — compiled against an older version of Apple's Metal Performance Primitives — assumed bfloat and half precision types were interchangeable, but they no longer are. The crash occurs even when forcing CPU-only mode with OLLAMA_NUM_GPU=0 , making the issue a blocker for all inference on affected systems until an official fix is released.
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Source: r/ollama | 2026-04-15