"Unknown resource" error

If this template helps then use it. If not then just delete and start from scratch.

OS : Win 10 Pro
PsychoPy version : 2026.1.3
Standard Standalone Installation: Yes
URL of experiment: nback_experiment [PsychoPy]

I’m getting an “unknown resource” error when piloting my experiment (need to buy credits for running it), for a conditions file used in a practice loop:

Unfortunately we encountered the following error:
- when importing condition: conditions_practice.xlsx
- when getting the value of resource: conditions_practice.xlsx
- unknown resource

I’ve ruled out the usual suspects:

  • The file exists in html/resources/ locally and on the Pavlovia GitLab repo (confirmed via the file browser)
  • It’s correctly named with no spaces/special characters (originally named conditions_practice (1).xlsx, renamed to conditions_practice.xlsx — confirmed updated in the loop’s Conditions field, in Experiment Settings → Online → Additional Resources, in the compiled nback_experiment.js, and in the resources folder itself)
  • I’ve Synced multiple times after each change
  • Tested in an incognito window to rule out browser caching (confirmed not caching — error message itself updated to reflect the new filename after rename)

When I checked the browser’s Network tab while piloting, no request for the .xlsx file is ever attempted at all — no 404, no failed fetch, nothing. The error appears to happen before PsychoJS tries to download the resource.

I also checked config.json directly (via the Network tab → Preview), and it contains no resources array at all — just experiment, pavlovia, and gitlab metadata:

json

{
    "experiment": { "name": "nback_experiment", "fullpath": "elang/nback_experiment" },
    "pavlovia": { "URL": "https://pavlovia.org/" },
    "gitlab": { "projectId": 530338 }
}

I also tried clearing the Output path field in Experiment Settings → Online (per a fix suggested for a similar issue in another thread), re-synced, and got the same error.

When I click on your link, I get


which suggests that you might have a lib folder.

Try deleting it, resyncing, and setting the experiment to inactive then active again.

Are you running the latest version?