List remote refs failed: com.jcraft.jsch.JSchException: Algorithm negotiation fail

After GitHub "has disabled support for weak encryption" [ https://githubengineering.com/crypto-deprecation-notice/ ] in [ https://github.com/Microsoft/Git-Credential-Manager-for-Windows ] my TeamCity lost connection with Git:

"List remote refs failed: com.jcraft.jsch.JSchException: Algorithm negotiation fail"

I had a update Github in server/slaves and changed register entries. And, I tried update jsch lib to last "jsch-0.1.54.jar" [ "Algorithm negotiation fail" with SSH authentication on TeamCity ], but doesn't works.

My env:

• Teamcity Professional 8.1.4 (build 30168)
• Windows 2008 Server R2 x64
• Git version 2.16.1.windows. (x64)

I had the same issue (I was on 9.0.1, however), upgrading to jsch-0.1.54.jar did not help either.

Ended up upgrading to version 10.0.3 and that fixed everything. Upgrading is very simple.

1. Download the .tar.gz of the specified version you want to upgrade to
2. Copy your current server.xml
3. Untar the file somewhere on your server where you want it to sit
4. Paste the server.xml configuration into the new version under conf/
5. Restart the TeamCity process (if you're using something like systemd to manage the process)

If not using systemd or some other similar daemon manager, just launch the process however you normally launch it.