This happens for me with the portable version on Windows 10.
- In the folder “010 Templates”, create a template “common.bt” with the following content:
InvalidStruct field;
- In the folder “010 Templates\folder”, create a template “file.bt” with the following content:
#include "../common.bt"
- Launch 010 and open some binary file as well as both template files.
- Run file.bt on the binary file. As expected, we get an error about the invalid structure type - however, it offers us to open common.bt even though this file is already open.
- Click “Load”. Sure enough, we get a second “common.bt” tab.
- Make some change in this tab and save the file.
- Click on 010 in the taskbar to move it to the background, then click it again to bring it back to the foreground. 010 freezes and has to be terminated through Task Manager.