Pavlovia server error 500 while saving data from jsPsych

jsPsych version (e.g. 6.0.0):


since yesterday (Thursday 2023-02-02), I cannot save collected data to the Pavlovia server anymore.
I follow exactly the instructions for running jsPsych experiments from Pavlovia ( Pavlovia), but use a slightly older version (jsPsych 6.0.0 and jspsych-pavlovia-2020.4.js, which I have saved locally in my experiment folder), which has worked completely fine in the past months up until yesterday.
I also reverted to a commit from Tuesday when it still did work, but I now get the same error.
All my codes runs fine if I host it locally on VS Studio, it really seems to be about the Pavlovia saving the data.
I call the respective custom function (save_data() which runs pavlovia_init and pavlovia_finish etc.) both at the end of the experiment and when participant press the “exit study” button prematurely; so I can easily manipulate when the task is finished and thus how much data is stored; and it crashes even if I exit immediately at the start and nothing gets stored.

Currently, on the last screen while saving the data (using the code suggested by ), I get the following error:

### [jspsych-pavlovia plugin 2020.4] Error

* when uploading participant' results for experiment: mkleinflugge/fishexpl_weffort_pavlovia
* **error**

and the console says

jquery-3.3.1.min.js:2          POST 500
jspsych-pavlovia-2020.4.js:545 error: error 
jspsych-pavlovia-2020.4.js:39 [pavlovia 2020.4] 
{origin: '_uploadData', context: "when uploading participant' results for experiment: mkleinflugge/fishexpl_weffort_pavlovia", error: 'error'}

This seems to be an error 500, so server-related?
Is this anything I could somehow fix myself or is this a problem on Pavlovia’s end?
Any help is much appreciated!
Best regards,