Variable create/edit dialog should populate combobox dropdown with existing variable names for the variable type selected.
Tried removing either one of both of the braces. Still could not generate a hang.
I don't think ampersand is the problem. You had another variable in there with & in its name for example. I couldn't reproduce any hang. When hitting reset, it did mention that there was no integral attached to Bonds_{HH\&F}, but it was clearly fixable by copying the actual stock variable Bonds_{HHF} (presumably because it was renamed) from the variable browser. Not sure if we need to add "stock" to the list of variable types in the variable create/edit window. My initial thought to rename the variable...
See also https://sourceforge.net/p/minsky/features/230/
Always On Top setting for Browser window
https://sourceforge.net/p/minsky/features/196/
Browser box needs scroll bars
Browser window improvements