In calltree panel, moving cursor to some depth of hierarchy results in error

[hrcHarry]

Hi

I open the calltree the expand the hierarchy of the call like (where symbol | denotes the cursor)

|+ outer_fun
   + inner1_fun1
     + inner2_fun1a
     + inner2_fun2a
   + inner1_fun2
     + inner2_fun1b
     + inner2_fun2b

I get the situation: When the cursor | moves to inner2_fun1a and inner2_fun2a, it might be fine. But when | moves to inner2_fun1b and inner2_fun2b, it results an error

How to fix the situation like this? Thanks.