# .mdc files in .cursor/rules/ not or rarely writeable by Cursor Agent

**URL:** <https://forum.cursor.com/t/mdc-files-in-cursor-rules-not-or-rarely-writeable-by-cursor-agent/67250>\
**Category:** Bug Reports\
**Created:** [March 20, 2025, 6:32am UTC](https://forum.cursor.com/t/mdc-files-in-cursor-rules-not-or-rarely-writeable-by-cursor-agent/67250 "2025-03-20T06:32:14Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![xblabs](https://sea3.discourse-cdn.com/cursor1/user_avatar/forum.cursor.com/xblabs/32/31094_2.png) [@xblabs](https://forum.cursor.com/u/xblabs)\
**Post date:** [March 20, 2025, 6:32am UTC](https://forum.cursor.com/t/mdc-files-in-cursor-rules-not-or-rarely-writeable-by-cursor-agent/67250/1 "2025-03-20T06:32:14Z")

</div>

Windows 10 Pro x64  
Cursor 0.47.8

Problem :

A) let Agent create a file that is not existing yet in .cursor/rules/ by explicit folder reference. It proceeds with the output and the confirmation that it successfully wrote the file but it did not. When asked it replies : “Yes, it appears there might be an issue with writing to the MDC files in the .cursor/rules/ directory.”

B) Let Agent write into an existing file .cursor/rules/test.md by explicit file reference. Same result as above

In both cases a popover / tooltip shows in the left side bar “OPEN EDITORS” tab : “1 unsaved changes” . the tip disappears and no trace of any change to be found despite the diff and everything being correctly shown in the agent / chat pane.

Only closing the mdc file and reopening it shows the changes , BUT also not always. Sometimes only restart of Cursor shows the changes.

---

<div class="post-metadata">

**Author:** ![Biggs](https://avatars.discourse-cdn.com/v4/letter/b/e274bd/32.png) [@Biggs](https://forum.cursor.com/u/Biggs)\
**Post date:** [March 28, 2025, 12:58pm UTC](https://forum.cursor.com/t/mdc-files-in-cursor-rules-not-or-rarely-writeable-by-cursor-agent/67250/2 "2025-03-28T12:58:49Z")

</div>

Fixed here: [Cursor agent cannot write to .cursor/rules files - #5 by jazzmind](https://forum.cursor.com/t/cursor-agent-cannot-write-to-cursor-rules-files/61732/5)

---

<div class="post-metadata">

**Author:** ![Biggs](https://avatars.discourse-cdn.com/v4/letter/b/e274bd/32.png) [@Biggs](https://forum.cursor.com/u/Biggs)\
**Post date:** [April 20, 2025, 3:13pm UTC](https://forum.cursor.com/t/mdc-files-in-cursor-rules-not-or-rarely-writeable-by-cursor-agent/67250/3 "2025-04-20T15:13:48Z")

</div>

Update 0.49.x makes the fix above not required any more. We can easily update .mdc files.

---

<div class="post-metadata">

**Author:** ![system](https://sea3.discourse-cdn.com/cursor1/user_avatar/forum.cursor.com/system/32/99069_2.png) [@system](https://forum.cursor.com/u/system)\
**Post date:** [May 20, 2025, 3:14pm UTC](https://forum.cursor.com/t/mdc-files-in-cursor-rules-not-or-rarely-writeable-by-cursor-agent/67250/4 "2025-05-20T15:14:04Z")

</div>

Closed on May 20, 2025, 3:14pm UTC

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.