> 1) A colleague tried to open the script file with the same version of Inquisit 5 in an iMac. The experiment could run fine, however he could see multiple repetitions for each line of the script (that are not part of the original version).
The Inquisit 5 Lab editor is not compatible with macOS Big Sur, and the repeated lines are a consequence of that. If need be, the script can be viewed using the trial version of Inquisit 6 Lab under Big Sur.
2) The experiment has a between subject design with 24 conditions and permutations assigned with groupnumber (random assignment without replacement). However the data collected in the pilot study (https://mili2nd.co/vkyb)
don't have all the conditions evenly distributed.
> Some participants quit before completing or even loading the experiment...this may disrupt the number assignment maybe?
Correct. A groupnumber is generated when somebody visits the experiment's start page, regardless of whether that person ends up starting or completing the study. This can (and under real-world conditions typically will) lead to some imbalances across groups, unequal amounts of participants per group.
> Is there a way to control this so only the completed experiments count in the condition assigned?
No. The only thing you can do is to pre-assign conditions to your participants and pass the groupnumber in via URL parameter. This of course is only workable if you know your participant pool in advance.