I am trying to run an experiment on pavlovia. After encountering many “runs” that involved a blank white screen, I deleted my project folder from Gitlab and started again with a new project in a new folder (on my desktop - rather than a cloud drive). The new experiment is extremely simple. It presents three screens of text (black background, white text) for one second each. There are no images. There are no responses. There are no custom code components. I can run it just fine locally (the python run). It syncs to pavlovia without issue. It runs on pavlovia (in pilot mode, it produces datafiles that download at the end of a run; in run mode, it logs datafiles). The issue is that when it runs, all I see is a blank white screen. Then the run ends normally.
I have tried running in several browsers (Chrome and Safari) on different computers (both MacOS: Tahoe 26.5.1). I am using the most recent version of Psychopy (standalone 2026.1.3) .
The console log produces a warning for each of my elements - that the size is undefined. I am not new to Psychopy or Python (my JS knowledge is very basic). This is a problem that I have never encountered before. I have deleted all the ‘html’ documents from the folder and re-synced the project several times. Any thoughts on what might be going on? (Thank you in advance).
