"The latest REST API version this server supports is 7.0."
A script or tool called your Azure DevOps Server with an api-version newer than the server knows. The server refuses the call with HTTP 400 and names the newest version it has. Send that version instead.
The whole answer
HTTP 400
{
"message": "The requested REST API version of 9.9 is out of range for this server. The latest REST API version this server supports is 7.0.",
"typeKey": "VssVersionOutOfRangeException",
...
}
The first number is what was sent, the second is the server's newest version. Tools often show just the message, or just "HTTP 400".
What each server said
We installed each server fresh (Express editions, October 15–16, 2026) and called {collection}/_apis/projects?api-version=9.9:
| Server | Newest version in the answer |
|---|---|
| Azure DevOps Server 2022 (first release) | 7.0 |
| Azure DevOps Server 2020 Update 1 | 6.1 — but see "is under preview" |
| Azure DevOps Server 2019 Update 1.1 | 5.1 |
| Team Foundation Server 2018 Update 3 | No such message: an HTML page, see "Page not found" |
How to fix the call
- Put the number from the message into the call:
?api-version=7.0. - If the number has a minor part such as 6.1 or 5.1, a part of the API may still treat it as a preview. On Azure DevOps Server 2020 Update 1, the Git calls refused 6.1 and worked with 6.0.
- For a script that talks to several servers: on HTTP 400 with this message, read the number, retry once with it, and keep it for that server.
Microsoft's version table: REST API versioning for Azure DevOps (2022 has 7.0, 2020 has 6.0, 2019 has 5.0, TFS 2018 has 4.0).
In IntelliJ IDEA, Rider and the other JetBrains IDEs
Azure DevOps Pull Requests is a pull request plugin for JetBrains IDEs 2024.1 or later. It reads this answer and steps down to the server's version by itself. On each server above it then ran the whole review: inbox, diff, comments, votes, completing. Reading is free; voting, commenting and completing are Pro, with a 30-day trial.
Get it on JetBrains Marketplace
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