Crash in QtCreator on creating new source file in some project subfolder

Log:

SOFT ASSERT: "item" in file /work/build/qt-creator/src/libs/utils/treemodel.cpp, line 1125
SOFT ASSERT: "item" in file /work/build/qt-creator/src/libs/utils/treemodel.cpp, line 1125
Segmentation fault

Crash usually happens on attempt to create new source file (.c or .h) in some project subfolder. The project should be some 'imported' project.
Crash doesn't happen when file is created in the root directory of the project, but almost always happens when file is created in some subfolder.
Also crash doesn't happen in other project types (qbs, qmake, etc).
Bug also was reproducable on stable 4.7.0 version

Steps to reproduce:

• Import some C/C++ project (New project - Import project - Import existing project)
• Create new file (.c or .h) in some project subfolder

Expected results:

• File is created

Actual results:

• File is created, but qtcreator is crashed.

Screencast with bug recorderd:
https://www.youtube.com/watch?v=bUsyf2ABDiU