I am using an EMX for developing. I write a small application for upgrade, in this application, it puts the development device to bootloader mode. After then I could not deploy my another project to the device. The size of the binaries (an exe + dependency dlls) is about 650KB. When I change the device to application mode, I could deploy my project to device.
When you use in field update, the size limited. The update application shouldn’t do much other than updating. 650KB is very big… of the 650KB do you need all of it? Try removing some unsed assemblies.