You will need to first install magicdesign from here, and then run magicdesign::magicdesignee() in R. The Shiny app should appear in your default browser.

You can access magicdesignee here.

There are several possibilities: the design is too much for the Shiny app server, the Shiny app has run out of its 25 hours of free monthly allowance, or the Shiny app has encountered a bug. It can be hard to identify the issue, so please report it to me along with its error messages.

You can either reduce the width of the browser window or download the plot using the button provided on top of the plot. The downloaded plot should have clearer font sizes.

The replicates from the last crossing generation are not displayed. It is just a mean to minimize clutter and hopefully easier to see the pedigree.

The computation time depends on the designs and number of simulations. It can be slow with many crosses and large populations, for example, more than 1,000 total crosses/individuals. It is recommended to start with small number of simulations (like 10) if you are going to use a design with large number of crosses and individuals. If everything looks fine, then just let the Shiny app takes its time if you want to use a higher number of simulations. Please consider using the local version because the web version is slow and can be unstable depending on your network connection.