anthropics
[BUG] Sessions become unresponsive after upgrade to 2.0.60 (suspected background agent blocking)
Preflight Checklist
- [x] I have searched existing issues and this hasn't been reported yet
- [x] This is a single bug report (please file separate reports for different bugs)
- [x] I am using the latest version of Claude Code
What's Wrong?
Platform: Linux (Ubuntu 24.04)
Description: After upgrading to 2.0.60, both resumed and fresh conversations randomly become completely unresponsive. The prompt appears active but accepts no input. No error message is displayed.
Symptoms:
- Prompt silently stops responding to user input
- ESC does not interrupt - prompt remains dead
- Some slash commands still work (/context) but others don't
- User input appears to be queued but not processed
Reproduction Evidence: When I manually logged out of my Anthropic account in a separate terminal session, the stuck session immediately displayed two backlogged prompts with "Invalid API key" errors - proving input was being queued but not processed:
ULTRATHINK Let's test the comment tool more... ⎿ Invalid API key · Please run /login
/end is running… ⎿ Invalid API key · Please run /login
Suspected Cause: The new "background agent support" feature (from 2.0.60 release notes: "Added background agent support. Agents run in the background while you work") may be silently blocking the main input loop while waiting on something. In the above example however the whole conversation was static for at least an hour, until I got the idea to re-log.
Workaround: None found, except to log out of anthropic and back in.
Related but different issues found:
- https://github.com/anthropics/claude-code/issues/4580 - Agent freeze but with 100% CPU (yours is silent)
- https://github.com/anthropics/claude-code/issues/10210 - Background tasks not notifying properly (closest match, but different symptom)
- https://github.com/anthropics/claude-code/issues/10481 - UI freeze on 2.0.28 macOS (different version/platform)
Issue is distinct because:
- Silent freeze (no CPU spike)
- Specifically on 2.0.60 with new background agent feature
- Linux platform
- Input queues but doesn't process (proven by the logout test showing backlogged prompts)
What Should Happen?
Prompt stays responsive. Background work shows visual feedback. No silent blocking.
Error Messages/Logs
Steps to Reproduce
- Upgrade to Claude Code 2.0.60
- Start a session (fresh or resumed - both affected)
- Work normally for a while (issue is intermittent)
- At some point, the prompt stops responding to input
- Try ESC - no effect
- Try typing - no response
- Some slash commands work (/context) but user prompts do not
To prove input is queued (not dropped): 8. In a separate terminal, run: claude logout 9. The stuck session immediately shows backlogged prompts with "Invalid API key" errors
Claude Model
Opus
Is this a regression?
I don't know
Last Working Version
No response
Claude Code Version
2.0.60
Platform
Anthropic API
Operating System
Ubuntu/Debian Linux
Terminal/Shell
Other
Additional Information
No response
I started getting the same thing, immediately after getting the update to this version. I also use multiple terminals running claude code at once, so maybe that is a contributing factor? they seem to become unresponsive very quickly, a few messages in sometimes.
I'm on MacOS 15.7.2
Experiencing the same here. No sub-agents, but when 1+ Claude Code CLI is established in IDE, all but one silently hang with no resolution but to close and restart chat, but then within minutes all fail but just one.
Also running into this since 2.0.60. Was not happening until the upgrade
Same here, even tried rolling back to 2.0.59 and it does not solve the issue :(
I experience the same problem, I got it in 2.0.57 version too yesterday, it's all the same freezing in 57 & 60!
@smconner Is it just unresponsive or the speed is also affected while thinking? For me coding work is going very slow even on Sonnet 4.5.
also having this issue, anyone see if there is a version we can roll back to that fixes?
This is happening in all versions, I am on 2.0.54, and it is happening on max plan. To be honest, this looks like more blocking us from using multiple terminals with claude at once...
Yeah it's completely broken now. Nothing works at all. It has become competently fucked up. All sessions hangs in an unrecoverable state after 1-3 minutes
This is happening in all versions, I am on 2.0.54, and it is happening on max plan. To be honest, this looks like more blocking us from using multiple terminals with claude at once...
Interesting hypothesis. That would be a deal breaker if true.
Yeah it's completely broken now. Nothing works at all. It has become competently fucked up. All sessions hangs in an unrecoverable state after 1-3 minutes
If you have a session going, and you open and run claude. Boom, your current session is gone. Very weird...
This is happening in all versions, I am on 2.0.54, and it is happening on max plan. To be honest, this looks like more blocking us from using multiple terminals with claude at once...
Interesting hypothesis. That would be a deal breaker if true.
Totally, but at this point any shady tactics I can expect from Anthropic
This is getting a bit ridiculous. Work is grinding to a halt, claude code is highly degraded.
As a temporary measure.. i tried using vscode extension to do my parallel work instead and so far is working fine in v2.0.60.
I started getting this this morning, did some debugging to figure out it was the new version, dialed it back to Claude Code v2.0.55, and I'm still seeing the issue.
Making this system, I developed that's freaking amazing, absolute garbage! Anyone know a stable version?
I see someone writing that they got this working using VS Code, so I should confirm that I'm on cursor over WSL running or was running multiple sessions out of the same project with hooks to make sure the right responses went to the right sessions.
And I've seen folks say that 59, 58, and 57, are all problematic and I'm saying 55 is as well...Does seem to work fine single threaded but I intentionally wrote a lot of code to let it support multi-threaded so I could have seven different processes running or so.
Does anybody have a known version of cc that works multi-threaded, since down to 55 seems broken?
I've built a kind of neat research tool as part of this and lots of ideas answers in here I'm too tired to try them and hopefully anthropic fixes stuff But tomorrow I'll try 2.0.51 per this: https://reports.perceptionbuilder.com/geek/claude-code-version-stability-rollback_20251206.html
Quick note: cleaning ~/.claude subdirs as laid out in the doc above did not help me recover from .60 back to .55 so I will try .51 later.
How the heck does this get past all QA and internal Anthropic employees / users into the wild? I noticed this started about 14 hours ago, after a full day of successful building / refactoring.
Experiencing the same issue on macOS with Claude Max. My debugging findings:
Simple prompts work fine (e.g. "Hey, what's 2+2?" responds in 2 seconds) Workflows/slash commands that read multiple files hang indefinitely Tested with --dangerously-skip-permissions, --debug, and plain claude - all hang Network is confirmed fine (5ms ping to api.anthropic.com, no packet loss) API status shows all systems operational
Timeline: Started immediately after auto-update to 2.0.60 on Dec 6 Confirming the multi-terminal theory: I had multiple Claude Code terminals open when this started. The terminals running workflows that load multiple config files all hung at the loading animation ("Photosynthesizing...", "Flowing...", "Boondoggling..."), while a simple slash command in a fresh single terminal worked. This is a significant regression that's blocking real work. I've also opened #13254 with detailed reproduction steps. Anthropic - this needs urgent attention. Multiple users across macOS, Linux, and Windows are all dead in the water.
This bug is REALLY making me think about turning off automatic updates.
On Sun, Dec 7, 2025 at 8:14 AM hookey13 @.***> wrote:
hookey13 left a comment (anthropics/claude-code#13188) https://github.com/anthropics/claude-code/issues/13188#issuecomment-3621451646
Experiencing the same issue on macOS with Claude Max. My debugging findings:
Simple prompts work fine (e.g. "Hey, what's 2+2?" responds in 2 seconds) Workflows/slash commands that read multiple files hang indefinitely Tested with --dangerously-skip-permissions, --debug, and plain claude - all hang Network is confirmed fine (5ms ping to api.anthropic.com, no packet loss) API status shows all systems operational
Timeline: Started immediately after auto-update to 2.0.60 on Dec 6 Confirming the multi-terminal theory: I had multiple Claude Code terminals open when this started. The terminals running workflows that load multiple config files all hung at the loading animation ("Photosynthesizing...", "Flowing...", "Boondoggling..."), while a simple slash command in a fresh single terminal worked. This is a significant regression that's blocking real work. I've also opened #13254 https://github.com/anthropics/claude-code/issues/13254 with detailed reproduction steps. Anthropic - this needs urgent attention. Multiple users across macOS, Linux, and Windows are all dead in the water.
— Reply to this email directly, view it on GitHub https://github.com/anthropics/claude-code/issues/13188#issuecomment-3621451646, or unsubscribe https://github.com/notifications/unsubscribe-auth/AABWQMFOVAOXBLQ3CYBXMGT4AN5OXAVCNFSM6AAAAACOHD3VQCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTMMRRGQ2TCNRUGY . You are receiving this because you were mentioned.Message ID: @.***>
I switched to Sonnet using the /model toggle and it seems to be running more consistently.
Edit: I lied. Seems after 10-15 minutes of use, the "hanging" effect re-surfaces.
I'm experiencing a similar issue with a specific, reproducible trigger: opening a second Claude Code session in the same project directory.
Steps to Reproduce:
- Start Claude Code session in a project directory
- Open a second Claude Code session in the same project directory
- First session immediately gets stuck processing
- Press escape - session shows
>prompt with dark grey background - Any command typed is completely ignored - no response from Claude
Environment:
- Platform: Linux 5.15.0-157-generic
- Version: 2.0.45
Key difference from main issue: The trigger is consistent and reproducible - it happens immediately when opening a second session in the same project, rather than randomly during normal use.
This suggests the background agent blocking may be specifically triggered by session conflicts when multiple instances run in the same directory.
Related issue filed: #13268
We pushed out a configuration change at 10:49:50 PM (~1 hour 44 mins ago). For those of you who have been affected by this issue, do you still see it now? It seems like the issue is resolved for @thealbertyang and @weisisheng ?
We pushed out a configuration change at 10:49:50 PM (~1 hour 44 mins ago). For those of you who have been affected by this issue, do you still see it now? It seems like the issue is resolved for @thealbertyang and @weisisheng ?
Still same, just a screenshot of how the terminal behaves when it is stucked.
Basically the first terminal will become unresponsive (not doing anything, adding further prompts will show like the screenshot above) after the 2nd terminal is spawn. Both terminal are pointing at the same directory.
To reproduce,
- Open first terminal run claude, prompt it to do something
- Open second terminal as the first terminal is still running, prompt it to do something, on the same directory.
- First terminal will be unresponsive as shown in the screenshot.
Both are at version 2.60.0