I bumped into this crash when setting Minimum required SDK in the AndroidManifest.xml editor.
Steps to reproduce:
1) Open AndroidManifest.xml editor and change e.g. Minimum required SDK to some other value so that the title changes to AndroidManifest.xml* indicating that there are changes
2) Switch the active target/kit to Desktop Qt 5.5.0 GCC 64bit
3) Now try to save AndroidManifest.xml by pressing CTRL+S
4) Observe that Qt Creator crashes or (sometimes) the file seems not to be saved as the title is still AndroidManifest.xml*
I noticed that Qt Creator crashed also when I started to build without saving and Qt Creator opened the dialog asking whether I want to save AndroidManifest.xml because it had changes. I clicked "yes" and it immediately crashed.