Guitarix creates an error message while changing from one preset...

I get this error message when I click from one preset to another on Guitarix : gx_head 0.34.0. Here is the message: gx head fatal system error: guitarix fatal error *** std: exception: vector: m_range_check:_(which is 18446744073709551615)> size() (which is 3). Every time this happens, I have to close out of guitarix and restart it because of this message or if I do change between presets each time I do it I get the message repeatedly again, one per each change. I don't have this problem on Ubuntu 14.04, just Ubuntu 16.04. I am able to change between Rakarrack presets most of the time without this error but once in a while this error happens. I wonder if a volume overload produces this change. I'm using a Behringer FCB 1010 midi foot controller pedal board switch. I have Ubuntu 16.04. I'm using an Edirol UA25EX USB Sound Card at 48000 MHZ. My Rakarrack version is V0.6.1. My Guitarix version is GX_Head 0.34.0. My Q-Jack Version is Jack Audio Connection Kit QT-Gui Interface Version 0.4.2 with Build Apr 7 2016 21: 23:34.

My port settings on Guitarix are Audio: Racarrack Input System Capture 1&2, Audio Racarrack Output 1&2 are Rakarrack Aux on both. Also system playback 1&2 are enable in the Audio tab. In Guitarix Insert Rakarrack in 1&2 and out 1&2 and system playback and capture 1&2 are enabled. Also, in Guitarix Insert GX_Head FX in _0 and Amp out_0 are enabled. In the Guitarix Midi tab section Rakarrack MC: out and Rakrrack : in as well as both system Midi_Capture 1&2 and system Midi _Playback 1&2 are enabled.

Overall, My system works well. The only hickup seems to be the changing from one preset in Guitarix to another on the sub-presets within a given category. This is when the error message occurs.