Bug: Slash / menu hangs forever while marketplace plugin install stalls

Support Bug Reports
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1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Typing / in Agent chat shows an infinite loading spinner. Restart Extension Host and Reload Window do not fix it. Full quit (Cmd+Q) alone also does not fix it. The hang lasts until the marketplace plugin cache for the pinned commit is populated successfully (or the broken install is otherwise unblocked).

Impact
Slash commands and skills menu never finishes loading
Skills sync fails with Canceled
Agent/shell tooling can degrade in the same session

Steps to Reproduce

Enable marketplace plugins pr-review-canvas and cursor-sdk (backend pins both to the same commit).
Ensure cache for that commit is missing or empty under ~/.cursor/plugins/cache/cursor-public/…//.
Quit and reopen Cursor.
Open Agent chat and type /.
Observe infinite loading.

Expected Behavior

/ lists project commands (.cursor/commands) and skills promptly.

Operating System

MacOS

Version Information

Product: Cursor Desktop (macOS arm64)
Version: 3.13.25 (stable)
OS: macOS Darwin 25.6.0

Additional Information

Evidence from logs
File: ~/Library/Application Support/Cursor/logs//window1/exthost/anysphere.cursor-agent-exec/Cursor Plugins.log

Failing session pattern:

BackendMarketplaceClient: Adding enabled plugin: pr-review-canvas from 8185ad9fbb903efc7d1cf152a9be9777e516cfbc at pr-review-canvas
BackendMarketplaceClient: Adding enabled plugin: cursor-sdk from 8185ad9fbb903efc7d1cf152a9be9777e516cfbc at cursor-sdk
marketplace listEnabledPlugins completed in ~480–620ms (2 plugins)
loadFromMarketplaceSource: Plugin missing from cache, installing: pr-review-canvas at …/pr-review-canvas/8185ad9fbb903efc7d1cf152a9be9777e516cfbc
[cc-marketplace-import] cc-marketplace-import.readdirError
No marketplace cache or marketplace metadata, skipping cache check
'# ← no further success/failure for that install; empty cache dir left behind
Related agent-exec warning in the same session:

Failed to sync managed skills from dashboard {“error”:“Canceled: Canceled”}
After manually populating the cache for commit 8185ad9fbb903efc7d1cf152a9be9777e516cfbc and restarting, the same log shows:

loadFromMarketplaceSource: Found cached plugin: pr-review-canvas at …/8185ad9f…
loadFromMarketplaceSource: Found cached plugin: cursor-sdk at …/8185ad9f…
loadFromMarketplaceSource completed … (2 plugins loaded, 0 failures)
Plugins reload completed: 2 plugins loaded (0 extension), 0 failures
At that point / works again.

Environment checks (ruled out)
These were all healthy / not the cause:

Network: api2.cursor.sh → HTTP 200 (~110ms); no system proxy
Disk: ~258 GB free; plugin cache directory writable
Source commit fetchable outside Cursor (tarball link 1 below) → HTTP 200 (~3.3 MB)
Commit exists via GitHub API (link 2 below)
Project .cursor/commands is tiny (3 markdown files) and unrelated
Extension Host restarts log clean exits (code: 0) — restart works; hang is not in EH lifetime
Observed installer behavior
Backend enables both plugins at commit 8185ad9fbb903efc7d1cf152a9be9777e516cfbc.
Installer creates ~/.cursor/plugins/cache/cursor-public///.
Directory stays empty (no files, no .cache-complete).
Install never completes or logs a terminal error.
/ menu blocks waiting on plugin/skills enumeration.
Deleting empty dirs alone does not fix it — installer recreates empty dir and stalls again.
Manually copying plugin contents from that GitHub commit into the cache and adding .cache-complete does fix it after Cmd+Q reopen.
Also logged every boot (possibly related, not proven causal):

[cc-marketplace-import] cc-marketplace-import.readdirError

Workaround
Download the plugins tarball for the pinned commit (link 1).
Copy pr-review-canvas/ and cursor-sdk/ into:
~/.cursor/plugins/cache/cursor-public///
Create empty .cache-complete in each directory.
Fully quit Cursor (Cmd+Q) and reopen.
Alternative: disable pr-review-canvas and cursor-sdk in Settings → Plugins so install is never attempted.

Does this stop you from using Cursor

No - Cursor works, but with this issue

5

Hey, thanks for the report. We rarely see a case broken down this carefully, with logs, ruled out causes, and workarounds. That helps a lot.

Main point: the simplest workaround is to disable pr-review-canvas and cursor-sdk in Settings → Plugins. Then the install won’t run and the / menu loads normally. Your second option, manually putting the plugin contents into the cache and creating an empty .cache-complete, then restarting with Cmd+Q, also works if you need the plugins.

The behavior where install silently leaves an empty cache directory without a terminal error, and then recreates an empty folder on retry, is something we’re tracking on our side. But the fact that / and the skills menu then hang forever with no timeout looks like a separate issue. I passed that to the team together with your logs. I can’t give an exact ETA.

A couple quick questions so we can narrow it down:

  • Does the hang reproduce consistently on every cold start with an empty cache, or only sometimes?
  • After disabling both plugins, do / and the skills menu load normally right away?

If either workaround doesn’t work for you, tell me and we’ll dig in further.

6

@deanrie

For full transparency, the cursor agent worked itself through the fix. Then advised me to submit it here and produced the report, which explains the detailed report.

After experiencing the issue and prompting the agent past some false positives, it discovered the root issue. Then downloaded the plugins repo at the commit Cursor was trying to install, copied pr-review-canvas and cursor-sdk into the matching folders under ~/.cursor/plugins/cache/cursor-public/, added a .cache-complete file in each, then I fully quit and reopened Cursor so / would load without waiting on the broken install.

7

Thanks for coming back with details. Yep, now it’s clear where the deep dive came from. Also nice that the agent got to the root cause on its own.

Main point: your fix, prefill the cache for the pinned commit plus an empty .cache-complete, then Cmd+Q and restart, works. That’s exactly how this should be fixed in this scenario. If you don’t need plugins right now, disabling pr-review-canvas and cursor-sdk in Settings → Plugins also fully avoids the hang, since the install never starts.

There are basically two issues here: a silently stuck install that leaves an empty cache directory with no terminal error, and then / plus the skills menu hang with no timeout. I shared both with the team along with your logs, and we’re tracking it. I can’t share an exact ETA yet.

If you hit the hang again on a cold start with an empty cache, message me. I’d like to know if it reproduces every time or only periodically. Let me know if any of the workarounds stop helping.