If the error prompts "Abnormal library path permissions detected", this usually means the application doesn't have the permission to create or edit the files in the library.

If you are encountering the situation, please try troubleshooting steps as described below:

Check the library folder isn't "Read-only".
Check the library folder "Security" settings. Make sure the current user has "Full control" of the path.

When encountering issues with Eagle not being able to create files/folders, or having any permission issues for editing or adding, it is likely related to the following situations:

Hard Drive Using Non-Native Formats (APFS, HFS+)

If your hard drive is formatted as NTFS, this format only supports reading and does not support writing operations. For more information, please check: External Hard Drive Library Compatibility between macOS and Windows. It is recommended that you convert the hard drive format to APFS or HFS+, which usually resolves the issue.
Using Third-Party Hard Drive Plugins

If you are using NTFS formatted hard drives between different operating systems via Tuxera NTFS or Paragon NTFS plugins, make sure your plugins are up to date. However, to avoid possible performance degradation caused by these plugins, we do not recommend using them on macOS. For detailed reasons, please check: Why we don't recommend using Tuxera NTFS / Paragon NTFS on macOS?
External Hard Drive Hardware Issues

If you are using an external hard drive formatted in a native format but still encounter problems, please check if the USB extender you are using is unstable. It is recommended to try connecting the external hard drive directly to the computer.
Incorrect Permission Settings

If none of the above situations apply, it may be due to incorrect permission settings for the library folder. You can check it as follows:
- Right-click on the library folder > Get Info, and check if the file is set as "Locked" (please uncheck it) and whether the logged-in user on the computer has "Read & Write" permissions for that path.
- Use "Finder" to open the library folder, try copying a file from another folder, and paste it into this path; also try creating a folder in this path.

After you open Eagle, it shows prompt message "Abnormal library path permissions detected"