Backport: docs: add troubleshooting for v1 provider migration (#9876)

This is an automated backport of #9870 to the release-v5.0 branch.

Co-authored-by: Nico Albanese <49612682+nicoalbanese@users.noreply.github.com>

Author: vercel-ai-sdk[bot]

content/docs/09-troubleshooting/19-unsupported-model-version.mdx

@@ -0,0 +1,50 @@
+---
+title: Unsupported model version error
+description: Troubleshooting the AI_UnsupportedModelVersionError when migrating to AI SDK 5
+---
+
+# Unsupported model version error
+
+## Issue
+
+When migrating to AI SDK 5, you might encounter an error stating that your model uses an unsupported version:
+
+```
+AI_UnsupportedModelVersionError: Unsupported model version v1 for provider "ollama.chat" and model "gamma3:4b".
+AI SDK 5 only supports models that implement specification version "v2".
+```
+
+This error occurs because the version of the provider package you're using implements the older (v1) model specification.
+
+## Background
+
+AI SDK 5 requires all provider packages to implement specification version "v2". When you upgrade to AI SDK 5 but don't update your provider packages to compatible versions, they continue using the older "v1" specification, causing this error.
+
+## Solution
+
+### Update provider packages to AI SDK 5 compatible versions
+
+Update all your `@ai-sdk/*` provider packages to compatible version `2.0.0` or later. These versions implement the v2 specification required by AI SDK 5.
+
+```bash
+pnpm install ai@latest @ai-sdk/openai@latest @ai-sdk/anthropic@latest
+```
+
+For AI SDK 5 compatibility, you need:
+
+- `ai` package: `5.0.0` or later
+- `@ai-sdk/*` packages: `2.0.0` or later (for example, `@ai-sdk/openai`, `@ai-sdk/anthropic`, `@ai-sdk/google`)
+- `@ai-sdk/provider` package: `2.0.0` or later
+- `zod` package: `4.1.8` or later
+
+### Check provider compatibility
+
+If you're using a third-party or custom provider, verify that it has been updated to support AI SDK 5. Not all providers may have v2-compatible versions available yet.
+
+To check if a provider supports AI SDK 5:
+
+1. Check the provider's package.json for `@ai-sdk/provider` peer dependency version `2.0.0` or later
+2. Review the provider's changelog or migration guide
+3. Check the provider's repository for AI SDK 5 support
+
+For more information on migrating to AI SDK 5, see the [AI SDK 5.0 migration guide](/docs/migration-guides/migration-guide-5-0).