I left CB in favor of other IDE's as codelite and qtcreator, but I return to it 6 months later.
I ran in the same problems. I ran apt-get install --reinstall codeblocks:
I ran in on :
x86_64 x86_64 x86_64 GNU/Linux, Ubuntu 16.04.1 LTS
I have CB 13.12 Built Oct 23 2015 22:44:30 wx3.0.2
When I open a project.
The project folder let side, clicking on tree files does not highlight files, though it opens files.
The tab control on top of MDI frame does not shows file titles (Shows empty tabs).
Cycling to View Show Editor Tabs / just makes the things worst.
Just install ubutu 16 ,the apt-get install codeblocks. make a project with 3 files. Try to navigate
trough the project files, either from project tree and / or from top tabs file names.
You'll see yourself the problems. Is practically unusable.