When writing a program to an HMI you may see the below error that "memory is short." It is important to read the details of the error message to see what specific area of memory is short. Referring to the below screenshot, we can see that there are a number of different memory sources which can cause the error. 

In this example, we can see that USB capacity of the project is set for 1 but the target device (which is the HMI panel) is 0. Simply put, the HMI needs to have a USB memory stick installed in order for the program to write. 

Below is the storage settings window for the HMI project. Here we can see that the alarm, logging, and recipe data, are all set to backup onto the USB stick.