Description of problem:
The following tutorials crash when opening:
Inkscape: Shapes
Inkscape: Advanced
Elements of Design
Tips and Tricks

Version-Release number of selected component (if applicable):
inkscape-0.92.3-1.fc28  

How reproducible:
Always

Steps to Reproduce (via gui):
1. Click Help > Tutorial >

Actual results:
Inkscape encountered an internal error and will close now

Expected results:
The tutorial opens

Additional info:
The following files crash when opening inkscape via terminal:
/usr/share/inkscape/tutorials/tutorial-advanced.svg
/usr/share/inkscape/tutorials/tutorial-elements.svg
/usr/share/inkscape/tutorials/tutorial-shapes.svg

Message:
/usr/include/c++/8/bits/stl_vector.h:950: std::vector<_Tp, _Alloc>::const_reference std::vector<_Tp, _Alloc>::operator[](std::vector<_Tp, _Alloc>::size_type) const [with _Tp = Inkscape::Text::Layout::Character; _Alloc = std::allocator<Inkscape::Text::Layout::Character>; std::vector<_Tp, _Alloc>::const_reference = const Inkscape::Text::Layout::Character&; std::vector<_Tp, _Alloc>::size_type = long unsigned int]: Assertion '__builtin_expect(__n < this->size(), true)' failed.