Hey, thanks for the report. This is a known issue related to the filesystem and markdown files created by the Agent.
Related thread: Create/Update .md files -- Unable to open: Assertion Failed: Argument is ‘undefined’ or ‘null’
Your analysis matches what we’ve seen: the problem is in how Cursor handles files created by processes running in the Agent execution context.
Workarounds:
- Create the markdown files manually before running the Agent, then ask the Agent to edit them
- After the Agent creates a file, open it in another editor, then copy the contents into a new file in Cursor
The team is already tracking this. Let me know if you can share any additional details.