Ollama silently drops a history message larger than its context window
In freemansoft/Flutter-AdaptiveCards a demonstration Dart chat server hands a question to a local Ollama model. It asks for the answer as Adaptive Card JSON, a strict, closed-vocabulary schema that a Flutter client renders as interactive UI rather than as text. A directory of probes measures which local models manage that and how well. Every one of those probes had been asking its question into a nearly empty context window. Each call carried a system prompt, one question, and at most a short seed exchange. A real conversation fills the window. What changes when it is full? Two findings came out of filling it, measured on an Apple M1 Max with 64 GB and an Apple M5 with 16 GB. Both hosts ran Ollama 0.33.3, and the M1 Max results reproduced under Ollama 0.34.0. What the runner allocates follows one rule , with no counterexample in fifty-one runs across the two Ollama versions. It is often not what the request asked for. A history m...