CourseRetrieval-Augmented Generation: The Complete Course · Module 4: Embeddings · part 34 of 95
Part 34 · Module 4: Embeddings

Incident: A model change the reset never saw

14 min read·13 Oct 2026
Module 4 · Incident file · About 30 minutes

What happened

ANYTHINGLLM, AN OPEN-SOURCE PROJECT Dec 2024 reset added PR #2819 Jan 2025 v1.4.0 gap begins 22 Sep 2026 gap reported issue #6460 25 Sep 2026 fixed PR #6461 about 20 months, one path unguarded
AnythingLLM added a reset for embedding model changes in December 2024 (green); one settings path skipped it from v1.4.0 (amber) until it was reported and fixed in September 2026.

AnythingLLM is an open-source application from Mintplex Labs for chatting with your own documents. In December 2024 a user asked how to clear documents after changing the embedding model (issue #2745, 1 December 2024). The answer was pull request #2819, merged on 16 December 2024. Its description says that changing embedding models or vector databases "causes mismatching of vector dimensions", so the change "clears the vector db of all vectors and purges all cached documents". From then on, changing the model on the settings page warned the user, then cleared the documents and vectors.

TWO FIELDS SET THE MODEL; ONE RESETS EmbeddingModelPref most embedders AzureOpenAi...Pref Azure deployment hook no hook warn, then reset old vectors cleared model setting only old vectors stay
Both fields changed the model the app embeds with (blue), but only one called the reset (green); the Azure path left the old vectors in place (red).

On 22 September 2026 a contributor reported that one path skipped both (issue #6460). With Azure OpenAI as the embedder, "changing only the embedding deployment name in Embedding Preference skips both the warning and the vector reset." The Azure form saved its deployment under its own field name, and that field wrote the model setting "without the handleVectorStoreReset hook". The report states the consequence: "the old vectors stay next to the new embedder." It dates the gap to v1.4.0, the release of January 2025.

REPORTER'S RUN ON V1.16.2, ONE DOCUMENT step documents vectors before 1 1 after Azure field 1 1 after generic field 0 0
The report's own test: changing the Azure field left the document and its vector (red); the generic field cleared both (green).

The reporter ran the real settings endpoint on v1.16.2 with one embedded document: after the Azure change, one document and one vector remained; after the generic field, none. They "did not run this against a live Azure resource", and the issue reports no affected users. The fix, pull request #6461, added the hook to the Azure field and was merged on 25 September 2026.

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