Hi, I have the same problem too. I was able to track down the problem. The problem is that for JtagICE mk1 in the jtag1 class there are 3 methods for handling breakpoints: addBreakpoint, deleteBreakpoint, updateBreakpoints. updateBreakpoint for jtag1 uses its own structures filled with addBreakpoint and deleteBreakoint, and should use the "bp" structure. The quickest fix for this error will be: --- a/avarice/src/jtag.h 2020-10-01 18:42:10.267554671 +0200 +++ b/avarice/src/jtag.h 2020-10-01 18:43:28.447174612...