[BUG] Invalid Version: 2.1.0 (2026-01-07)

Same here

I am having this same issue

Same

Edit: Since my comment is high up, workaround here:
https://github.com/anthropics/claude-code/issues/16673#issuecomment-3720643589

Same thing for me my session just crashed in the middle of a debug session and then when I tried to reopen it I get this issue

Confirming this issue.

Environment:

• Claude Code: 2.1.0 (native install)
• macOS (Apple Terminal)
• Node: v24.11.1
• TERM_PROGRAM_VERSION: 465

Stack trace excerpt:

ERROR  Invalid Version: 2.1.0 (2026-01-07)
- Pw (/$bunfs/root/claude:813:8909)
- CfD (/$bunfs/root/claude:813:14035)

The semver parser is choking on the date suffix in the version string. Likely needs semver.coerce() or stripping the date before parsing.

Workarounds attempted (none worked):

• unset TERM_PROGRAM_VERSION && claude
• TERM_PROGRAM_VERSION="1.0.0" claude

The issue is Claude Code's own version string, not the terminal's.

Found 2 possible duplicate issues:

1. https://github.com/anthropics/claude-code/issues/16671
2. https://github.com/anthropics/claude-code/issues/16672

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🤖 Generated with Claude Code

Same

same

Same

Same here on node 20.19.3

Same

same here

Node.js v23.11.0

Same

same issue

same

same

same

following

Same, following.

+1

hlep

same

same here

same

Same

Same

same

unusable it happened as soon as tried to get into a new conversation yikes can't even use and just bought a second max plan

Help suffocating without

Worked around by moving settings out of the way, then selectively restoring them. Also installed a particular version:

curl -fsSL https://claude.ai/install.sh | bash -s -- 2.0.76
mv ~/.claude.json ~/.claude.json.bak

Broke for me also.

flop

Worked around by moving settings out of the way, then selectively restoring them. mv ~/.claude.json ~/.claude.json.bak

Worked thanks

Worked around by moving settings out of the way, then selectively restoring them. mv ~/.claude.json ~/.claude.json.bak

Even with that it's still broken.

Workaround that worked for me:

rm -rf ~/.claude/cache
mkdir -p ~/.claude/cache
echo "# Changelog" > ~/.claude/cache/changelog.md
chmod 444 ~/.claude/cache/changelog.md

This creates a read-only placeholder that prevents the invalid changelog from being written. Claude starts fine after this.

Root cause seems to be the changelog getting cached with ## 2.1.0 (2026-01-07) which isn't valid semver - the (date) suffix breaks parsing.

Workaround that worked for me: `` rm -rf ~/.claude/cache mkdir -p ~/.claude/cache echo "# Changelog" > ~/.claude/cache/changelog.md chmod 444 ~/.claude/cache/changelog.md `` This creates a read-only placeholder that prevents the invalid changelog from being written. Claude starts fine after this. Root cause seems to be the changelog getting cached with ## 2.1.0 (2026-01-07) which isn't valid semver - the (date) suffix breaks parsing.

works for me!

Same

rm ~/.claude/cache/changelog.md worked for me!

Wow, the second clusterfuck within a week.

simpler workaround that worked for me: sed -i '' 's/\(## 2\.1\.0\) ([0-9-]*)/\1/' ~/.claude/cache/changelog.md

An ongoing Claude Code session was able to patch its own (minified) source, fixing the issue. It confirmed the issue was the changelog / semver parsing:

  Problem: Claude Code 2.1.0 crashes with Invalid Version: 2.1.0 (2026-01-07) because the CHANGELOG.md format changed to include dates in version headers (e.g., ## 2.1.0 (2026-01-07)). The code parses these headers as object keys and tries to sort them using semver's .gt() function, which can't parse version strings with date suffixes.

  Affected functions: W37, gw0, and an unnamed function around line 3091 that fetches recent release notes.

  Fix: Wrap version strings with semver.coerce() before comparison. Run these 4 sed commands on cli.js:

  CLI_JS="$HOME/.nvm/versions/node/$(node -v)/lib/node_modules/@anthropic-ai/claude-code/cli.js"

  # Backup first
  cp "$CLI_JS" "$CLI_JS.backup"

  # Patch 1: Fix ve2.gt sort (recent release notes)
  sed -i 's/Object\.keys(B)\.sort((Y,J)=>ve2\.gt(Y,J,{loose:!0})?-1:1)/Object.keys(B).sort((Y,J)=>ve2.gt(ve2.coerce(Y),ve2.coerce(J),{loose:!0})?-1:1)/g' "$CLI_JS"

  # Patch 2: Fix gw0 sort
  sed -i 's/sort((G,Z)=>Wt\.gt(G,Z,{loose:!0})?1:-1)/sort((G,Z)=>Wt.gt(Wt.coerce(G),Wt.coerce(Z),{loose:!0})?1:-1)/g' "$CLI_JS"

  # Patch 3: Fix W37 filter
  sed -i 's/filter((\[J\])=>!Y||Wt\.gt(J,Y,{loose:!0}))/filter(([J])=>!Y||Wt.gt(Wt.coerce(J),Y,{loose:!0}))/g' "$CLI_JS"

  # Patch 4: Fix W37 sort
  sed -i 's/sort((\[J\],\[X\])=>Wt\.gt(J,X,{loose:!0})?-1:1)/sort(([J],[X])=>Wt.gt(Wt.coerce(J),Wt.coerce(X),{loose:!0})?-1:1)/g' "$CLI_JS"

  Note: If installed via different method, adjust CLI_JS path accordingly (e.g., /usr/lib/node_modules/@anthropic-ai/claude-code/cli.js).

If you tell an ongoing CC session the fix, he can probably fix himself.

2.1.1 please 🙏 fix it @claude

It's definitely seems to be related to claude --resume and claude --continue but maybe not its in the same project new project seems like I can start it weird.

I love the instant activity, and workaround, here. This is still an opportunity to push for Claude to becoming open source :)

#luv

I love the instant activity, and workaround, here. This is still an opportunity to push for Claude to becoming open source :) #luv

That will never happen lol

Workaround that worked for me: `` rm -rf ~/.claude/cache mkdir -p ~/.claude/cache echo "# Changelog" > ~/.claude/cache/changelog.md chmod 444 ~/.claude/cache/changelog.md `` This creates a read-only placeholder that prevents the invalid changelog from being written. Claude starts fine after this. Root cause seems to be the changelog getting cached with ## 2.1.0 (2026-01-07) which isn't valid semver - the (date) suffix breaks parsing.

I'm glad this works for people but I would recommend against this, as once a fix is issued (presumably very soon), this could cause problems, especially if people using this fix forget to chmod the changelog back.

Additionally, overwriting the changelog with arbitrary text is something I just flat-out will not do, in the same way I won't pour wiper fluid directly into the crankcase of my car's motor.

fixed on https://github.com/anthropics/claude-code/pull/16683

reverting to 2.0.76, removed /cache, changelog and .claude.settings.json. still borked

@demfabris same

edit ~/.claude/cache/changelog.md and delete the date on line 3:

from:
## 2.1.0 (2026-01-07)

to:
## 2.1.0

I guess we know now that it's written in Ink given the crash logs

Additionally, overwriting the changelog with arbitrary text is something I just flat-out will not do, in the same way I won't pour wiper fluid directly into the crankcase of my car's motor.

How exactly does an arbitrary changelog file break anything? If it does - it's not a changelog.

Worked here like so:

echo "" > ~/.claude/cache/changelog.md && chmod 444 ~/.claude/cache/changelog.md

Fixed! Restart to update

Worked here like so:

echo "" > ~/.claude/cache/changelog.md && chmod 444 ~/.claude/cache/changelog.md

same issue.

same issue chat

Happened to me too. Deleted claude, tried to reinstall. Now it cannot reinstall, my system says "zsh: permission denied: claude" when I try to run it, yet I also cannot delete it.

If only I didn't do anything and just waited for 20 more minutes. Now I am not sure how to fix it.

Trying to install it now says "Could not install - another process is currently installing Claude. Please try again in a moment."

Updaete: was able to fix both.

To everybody saying "same" and "same issue": you can use the 👍🏻 react on the OP to signal you are experiencing it. This has the added benefit of not creating tons of noise that prevent people from discovering the workarounds.

If you want to subscribe you can still do so without posting; just click the "subscribe" button on the right.

The fixes are already in and identified!

This worked for me, for instance: https://github.com/anthropics/claude-code/issues/16673#issuecomment-3720689911

Try this as a temporary workaround: https://github.com/anthropics/claude-code/issues/16673#issuecomment-3720683740

Happened to me too. Deleted claude, tried to reinstall. Now it cannot reinstall, my system says "zsh: permission denied: claude" when I try to run it, yet I also cannot delete it. If only I didn't do anything and just waited for 20 more minutes. Now I am not sure how to fix it

the native installer now points to the old 2.0.76 and it works.

If the changelog workaround still fails for you, check your .claude.json file (in my case the global one in your home directory), there is a cachedChangelog key with the "bad" changelog there. If you see the bad version as the first entry, change it by removing the date, save it and it should work.

Looks like: "cachedChangelog": "# Changelog\n\n## 2.1.0\n\n- Added automatic skill hot-reload...

Lmao claude update went from 2.1.0 to 2.0.76

same

sed -i '' 's/## 2.1.0 (2026-01-07)/## 2.1.0/' ~/.claude/cache/changelog.md is a temporary fix

https://github.com/anthropics/claude-code/pull/16686

Lmao claude update went from 2.1.0 to 2.0.76

fixed for me

claude update went from 2.1.0 to 2.1.1 works for me now

Claude Code is not source available because they don't want us to see how crappy the code is 🥲

hhha

Claude Code is not source available because they don't want us to see how crappy the code is 🥲

You can see the source here, but it's minified
https://www.npmjs.com/package/@anthropic-ai/claude-code?activeTab=code

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