How do I prevent Tiny Death Star from crashing when trying to collect an imperial items reward?

Unfortunately, given the game's structure, there are practically no work-arounds for bugs. You can try a reinstall, but most people have had little luck getting their progress back after that.

About the only thing I can think of, try building one more any of the items and see if it works after that. It might force the program to rebuild a file in doing so. But, I'm spitballing on that one.

I'm seeing the same thing on WP8 and on Windows 8.1. I think this happens when you attempt to collect the reward for the LAST Imperial task, and the game code is not handling correctly the case when there are no more new tasks to give out. I'm seeing the same behavior (game crash) when I attempt to skip the last task.