1. Open a project and build it with MSVC.
2. Start debugging this and stop at a breakpoint.
3. Switch Creator to instruction-wise operation.
   The disassembler shows up.
4. Click left of a line to add a breakpoint.
   The breakpoint will be added to breakpoints view but you will not see a marker next to the line.

The disassembler should show a red dot for a breakpoint, just like the source code editor does.