Hello,
In the latest version of psychopy (2023.2.3), when I am using the interleaved staircase option as the loop type in the loop builder, I cannot load the conditions excel file.
However, when I try to load the same excel file in the random option as the loop type, the file does load.
Also, I installed a previous version of psychopy and the same excel file does load for the interleaved staircase.
So, I think it is a problem with the specific version.