L6 - MCP Server Failing Outdated MCP SDK

Short Course Q&A MCP: Build Rich-Context AI Apps with Anthropic
1

The MCP SDK needs to be updated as it is breaking with the current client code.

Traceback (most recent call last):
File “/home/jovyan/.cache/uv/archive-v0/wUt8Jq4wjzWGjjMfjMAC8/bin/mcp-server-fetch”, line 6, in
from mcp_server_fetch import main
File “/home/jovyan/.cache/uv/archive-v0/wUt8Jq4wjzWGjjMfjMAC8/lib/python3.11/site-packages/mcp_server_fetch/init.py”, line 1, in
from .server import serve
File “/home/jovyan/.cache/uv/archive-v0/wUt8Jq4wjzWGjjMfjMAC8/lib/python3.11/site-packages/mcp_server_fetch/server.py”, line 6, in
from mcp.shared.exceptions import McpError
ImportError: cannot import name ‘McpError’ from ‘mcp.shared.exceptions’ (/home/jovyan/.cache/uv/archive-v0/wUt8Jq4wjzWGjjMfjMAC8/lib/python3.11/site-packages/mcp/shared/exceptions.py)

1 Like
2

The server config file needs to pin the version of mcp-fetch-server that was used.

3

Please see this thread.

4

L6 fetch server crash (cannot import name 'McpError')

The fetch server downloads the newest mcp library, and version 2.0.0 broke it.

FIx
Tell it to use the older one — in /L6/mcp_project/server_config.json:

"fetch": {
    "command": "uvx",
    "args": ["--with", "mcp<2", "mcp-server-fetch"]
}

Save and re-run.

Screenshot 2026-08-09 at 18-45-41 Jupyter Notebook - Terminal
Screenshot 2026-08-09 at 18-45-41 Jupyter Notebook - Terminal1298×389 22.8 KB

1 Like
5

yes, indeed, there has been an important update. The 2026-07-28 Specification

Updates are ready to deploy so let’s expect the notebooks ready pretty soon!

Lesly - DLAI

6

It worked for me!

1 Like
7

We just updated changes :slight_smile:

8

Notebooks have been updated to work as expected.

Quick status: the errors you’ve been hitting (mcp.server.fastmcp import errors, McpError import errors, tool_use/tool_result mismatches) are due to a breaking update released by MCP on 2026-07-28, which changed parts of the SDK the course was originally built against. This isn’t something on your end, the environment genuinely needs a few extra steps beyond what’s shown in the videos to keep working with today’s package versions.

We’ve pushed markdown notes to this notebook with the exact commands needed to get things running again. Please check those notebooks for the updated instructions.

Thanks again for reporting, suggesting solutions and your patience!

Happy Learning!

Lesly - DLAI

1 Like