I was working on my fairly large application, when I copied a screen that was similar to what I needed and made some edits. I was unable to compile the program, because it could not find some __SingleUse constants. I closed the project, and then could not reopen it again. I got a dialog saying 'Object reference not set to an instance of an object'.
After hours of frustration, I was finally able to recover my project by manually editing the texts.xml file after comparing it with the .touchgfx file to see what the differences in single use texts were.
After this, I created a simpler version of an application that generates the same failure and created a support case with ST.
I have copied many screens in my application and edited them, and not had a problem. I'm not sure why I had this issue, but all I did was copy and paste a screen, which contained Single Use TextArea widgets and a button, as well as some interactions.
To recreate the error in my simplified version, I copied and pasted the existing screen, then deleted all of the interactions except one. I then got compiler errors related to Single Use textArea widgets, and when I closed the program I was no longer able to open it again. I got the dialog box 'Object reference not set to an instance of an object'.
This is a serious bug in that you can end up with an inoperable project that won't even load, so I am posting this as a warning to you. Do not copy and past a screen without first creating a backup of your project.
