Diagnosing the Load Project Failed (Id 10459) error in The Observer
Last updated: Nov 07, 2025
Project Open or Copy Error in The Observer
This error may also appear as “Project Copy Error”, “Cannot update the current project with the existing temporary project (Id 10465)”, or “Cannot create temporary project file (Id 10452)”.
It may be caused by one of the following:
- The file being opened is not a valid project file.
- The filename does not match after restoring from a backup.
- The project database file is damaged.
The file is not a project
A valid project in The Observer consists of a folder named after the project, containing multiple files and folders, including a .vop file. If you attempt to open a file by double-clicking outside of The Observer, ensure it’s a .vop file.
If the file is a Project Backup (with a .vpb extension), it must be restored via File > Restore Backup within The Observer. This will recreate the project folder and open the project correctly.
The project file has been renamed
If the .vop file is renamed and then a backup is made and restored, The Observer may not find the expected filename and display an error. Ensure the .vop filename matches the folder name. Correct this manually after restoration in the folder:
Default path: C:\Users\Public\Documents\Noldus\The Observer XT\Projects\ (or your designated custom folder).
The project database is damaged or corrupted
If the issue is not due to an invalid file or a mismatch, the project database may be corrupted. Use the backup copy included in the project folder, named restore.btn, to recover:
- Rename the current
.vopfile (e.g.,Study.vop→Study.vop.old). - Rename
restore.btnto match the original.vopfilename (e.g.,Study.vop). - Open the project in The Observer.
Note: If file extensions are hidden, enable them first:
- In Windows 10/11: Open File Explorer, click View, then check File name extensions.
- In Windows 7/8: Press Alt > Tools > Folder Options > View tab > Uncheck "Hide extensions for known file types".
Using restore.btn may result in loss of the most recent session, but earlier data will be preserved.
Reminder: Always make regular backups from File > Make Backup and store them on a separate drive or location.