Invalid MIME type / missing configuration file

URL of experiment: K / pavtest12 · GitLab

Description of the problem: I am unable to launch any experiment due to different bugs.

First, after the initial sync I was getting “invalid MIME type” errors when piloting my experiment. I noticed that the index.html file references a local lib folder which is missing in my repo, so I changed the URL from ./lib/psychojs-2022.2.3.css to

But this in turn causes the following errors:

I was unable to find any documentation regarding what this config.json file should contain, so I am humbly asking for some help with launching my experiment.

Hi @k22j,

I usually get an “invalid MIME type” error, when my builder version and the PsychoJS version are not matching. And I notice that this is also the case for you: Your builder / PsychoPy is version 2022.2.2, but your PsychoJS is version 2022.2.3. Maybe it helps if you either update your PsychoPy version or set the PsychoJS version to 2022.2.2.

I don’t think that you have to manually change any URLs in the index.html.

I changed the version of Psychopy to 2022.2.3, to match PsychoJS:
expInfo['psychopyVersion'] = '2022.2.3';

The problem with invalid MIME type still persists.

I’m wondering why the lib folder is not generated when i export HTML… This seems to be the main reason why my experiment doesn’t start, because there are 404 errors.

Did you just insert this code, or did you properly update the software?

Could update the repo, so I can have a look?

Hi, sorry for taking so long to reply. We ended up switching to offline experiments…

In the end, after I updated to the latest PsychoPy version (2022.2.4), the problem with MIME type still persists. I notice that my .js file was still referencing psychojs-2022.2.3.js

Again I switched to remote lib folder location… And then I get the “missing configuration file” error. So all the same as before. The latest version of my repo should be publicly visible here

I can replicate the problem. It is solved as soon as I change “Use PsychoPy version” from “latest” to blank and export a new JS file.