Severe UI freezing and lagging in specific projects over time Folder rename is the only temporary fix

Support Bug Reports
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1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

After working on a project for a while and having long conversations with the Agent, the entire Cursor UI becomes incredibly laggy and unresponsive. Buttons have huge delays, and typing/scrolling freezes. The rest of Cursor (other windows/projects) works perfectly fine, the lag is isolated to the specific project workspace.

Starting a new chat or deleting the index does NOT fix the issue. The ONLY workaround that temporarily solves the lag is renaming the project folder in Windows. When I rename the folder and open it again, Cursor treats it as a new project, and the UI becomes extremely fast and responsive again. This heavily implies that there is a severe memory leak or storage bloat issue related to workspaceStorage or the AI chat history database for that specific path.

Steps to Reproduce

Open a project and have long, extensive interactions with the Cursor Agent over several days/weeks.

Observe the UI becoming progressively slower and freezing.

Try to start a new chat (doesn’t help).

Rename the project directory in the OS and open it in Cursor.

Observe that the lag is completely gone.

Expected Behavior

The IDE UI should remain responsive regardless of how long the project has been worked on or how long the Agent chat history is. Cursor should properly garbage collect or archive old workspace data so it doesn’t choke the renderer process.

Operating System

Windows 10/11

Version Information

Latest Version

For AI issues: which model did you use?

All models

For AI issues: add Request ID with privacy disabled

Not applicable because this is a UI performance issue not a request error

Additional Information

I emphasize that simply starting a new chat does not fix the lag. The database seems to remain loaded in memory. I absolutely do not want to delete my old chats to fix this because I need my project history. Renaming the folder constantly is a terrible workaround. Please investigate the workspaceStorage bloat.

Does this stop you from using Cursor

Yes - Cursor is unusable

3

Hey, thanks for the detailed report. The folder rename pattern is a helpful clue, it really points to something tied to workspace data for that specific project path.

To dig deeper, I’ll need a few things:

  1. Your exact Cursor version: Help > About Cursor > Copy.
  2. In the affected project, open Process Explorer (Ctrl+Shift+P > “Developer: Open Process Explorer”) and send a screenshot. I’m mainly looking for what’s using CPU/RAM (extensionHost, ptyHost, shared-process, etc.).
  3. Go to %APPDATA%\Cursor\User\workspaceStorage, find the subfolder for the affected project, and share its size. Inside there should be a workspace.json with the project path, that’s how we can confirm the right folder.

As a temporary workaround, instead of renaming the whole project folder, you can try deleting only the matching subfolder in workspaceStorage (make a backup first if you want to keep the data). It’s basically the same effect as renaming, but without changing the project path. Note that the chat history for that workspace will be lost.

I’ll pass this info to the team. Let me know how it goes.

4

Hi, Same issue here, no need to describe the issue any further than above, its exactly the same. my cursor version is:

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image1206×811 61.5 KB

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workspace is 10mb, i dont want to get rid as i amin the middle of something to be honest.

i only updated today to get rid of the update popup and its been awful since :frowning:

Thanks