Visual stimuli in three different block designs

Hello everybody!
I have just started using Psychopy.
Could you please give me some advice?

I have attached my current issue.
The problem is I cannot run next stem from the first trial(named trial 2 on the attachment file).

I have 90 pictures for my experiment.
The pictures three categories. Neutral, Pleasant and Unpleasant.
I would like to randomize each category.
Also, I would like to randomize each picture on its category.

The Excel files are image_random, image1, image2, and image3.
There are 30 image paths in image1. image2 and image3 are also same way.
image_random has the path for image1, image2 and image3 only.

Please let me solve my issue soon.

OS: window 10test fMRI.psyexp (21.8 KB)

PsychoPy version : PsycoPy v3.0.0b13

Many thanks,

There’s a chapter on randomization with block designs in the book

https://uk.sagepub.com/en-gb/eur/building-experiments-in-psychopy/book253480

Thank you Jon,
Unfortunately, I don’t have the book.
If you don’t mind could you give me some useful hints to resolve it myself?
Thank you very much in advance.

Regards,