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Blocked by CORS policy

URL of experiment:
code: Sign in · GitLab

Description of the problem:
When I try to run the experiment, I get the following error:

The console reports the following errors/warnings:

Failed to load resource: the server responded with a status of 400 () Access to XMLHttpRequest at ‘’ from origin ‘’ has been blocked by CORS policy: No ‘Access-Control-Allow-Origin’ header is present on the requested resource.

core.js:68 error: undefined

log4javascript.min.js:1 FATAL unknown | {“origin”:“PsychoJS.start”,“context”:“when starting the experiment”,“error”:{“origin”:“ServerManager.openSession”,“context”:“when opening a session for experiment: djangraw/mmi-3level”}}

The part of this that seems most informative is “blocked by CORS policy: No ‘Access-Control-Allow-Origin’ header is present on the requested resource.,” but I’m not sure what that means. This experiment was working fine yesterday, and I haven’t updated it since. Any idea what might be going on?

Update: When I run another task that is executing properly, I see references to “djangraw/[TaskName]” in the console, but here I get “djangraw%2F[TaskName]”. Is there a server somewhere that has accidentally used the ASCII substitution for a slash when referencing this experiment? If so, how can I get it changed?

This should all be fixed now