Cursor incorrectly marks official Marketplace extensions as obsolete

Support Bug Reports
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Installing the extension thor85.vscode-lang-e100e300 (E100/E300 Eclipse language) fails in Cursor on Linux.
Cursor automatically marks it as obsolete in ~/.cursor/extensions/.obsolete, so the extension never loads, does not appear under installed extensions, and cannot be selected in the language picker.

Steps to Reproduce

  1. Download thor85.vscode-lang-e100e300-0.1.3.vsix from the VSCode Marketplace.

  2. Install into Cursor (via GUI or unpack into ~/.cursor/extensions/).

  3. Restart Cursor.

  4. Check ~/.cursor/extensions/.obsolete → entry is created:

{“thor85.vscode-lang-e100e300-0.1.3”:true}

  1. Extension never loads and does not appear under installed extensions.

Expected Behavior

Cursor should accept and load valid VSIX extensions (this extension works fine in VS Code). It should not be auto-marked as obsolete immediately after installation.

Operating System

Linux

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.4.5
VSCode Version: 1.99.3
Commit: af58d92614edb1f72bdd756615d131bf8dfa5290
Date: 2025-08-13T02:08:56.371Z
Electron: 34.5.8
Chromium: 132.0.6834.210
Node.js: 20.19.1
V8: 13.2.152.41-electron.0
OS: Linux x64 6.14.0-27-generic

Additional Information

Workaround: If I rename the extension folder and bump the version in package.json (e.g. 0.1.4-local), Cursor then loads the extension correctly and syntax highlighting works. So the bug seems related to Cursor’s handling of extension versioning / obsolete cache.

Does this stop you from using Cursor

No - Cursor works, but with this issue

2

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Cursor incorrectly marks valid Marketplace extensions as obsolete by adding them to ~/.cursor/extensions/.obsolete.
For example, the extension Trailing Spaces (shardulm94.trailing-spaces v0.4.1) is from the official VSCode Marketplace, but Cursor repeatedly moves it to the obsolete list, making it unusable.

At the same time, official versions of other extensions (e.g. thor85.vscode-lang-e100e300-0.1.3) are not added to .obsolete.
This suggests Cursor incorrectly treats some valid Marketplace versions as “local” or unsupported.

Steps to Reproduce

  1. On Linux, install Cursor.

  2. Install the extension shardulm94.trailing-spaces v0.4.1 from VSCode Marketplace.

  3. Close and reopen Cursor.

  4. Check ~/.cursor/extensions/.obsolete. Notice that shardulm94.trailing-spaces-0.4.1 appears there, despite being an official Marketplace release.

  5. Extension cannot load until the entry is manually removed.

Expected Behavior

Official Marketplace extensions should not be added to .obsolete.
They should remain installed and functional like other Marketplace extensions (e.g. thor85.vscode-lang-e100e300-0.1.3).

Operating System

Linux

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.4.5
VSCode Version: 1.99.3
Commit: af58d92614edb1f72bdd756615d131bf8dfa5290
Date: 2025-08-13T02:08:56.371Z
Electron: 34.5.8
Chromium: 132.0.6834.210
Node.js: 20.19.1
V8: 13.2.152.41-electron.0
OS: Linux x64 6.14.0-27-generic

Additional Information

  • Local or manually patched builds (like *-local) being added to .obsolete makes sense.

  • But Marketplace extensions like shardulm94.trailing-spaces v0.4.1 should never be treated as obsolete.

  • The behavior is inconsistent and causes official extensions to be broken until the user manually edits .obsolete.

Does this stop you from using Cursor

No - Cursor works, but with this issue

3

Hi @hakonhagland can it be that the VSCode marketplace extension is not compatible with current version of Cursor?

We use OpenVSX marketplace.