Hwi_Construct Failing with strange error code?

I have modified the pinInterrupt example for the CC2650DK and essentially removed the callbackfunction and replaced it with an HWI for edge detection on IOID6 (previously connected to LED4). I was having problems with the hwi creation in that if I had the error_block field set to null, the program would hit the exit breakpoint after calling the hwi_construct function. 

I resolved this issue by adding the error_block variable to record the error message and code but I can make no sense of it the error message string is: 0x1EB4 ""; and the error code is 0.

The program will now continue to run however I can never get it to enter the ISR which leads me to believe something with the hwi_construct failed.. Any ideas?

Edit: Also I tried statically creating the hwi in the .cfg file and the program just exits as was happening before.

My code is as follows:

/* XDCtools Header files */
#include <xdc/std.h>
#include <xdc/cfg/global.h>
#include <xdc/runtime/System.h>
#include <xdc/runtime/Error.h>

/* BIOS Header files */
#include <ti/sysbios/BIOS.h>
#include <ti/sysbios/family/arm/cc26xx/Power.h>
#include <ti/sysbios/family/arm/cc26xx/PowerCC2650.h>

#include <ti/sysbios/knl/Task.h>

/* TI-RTOS Header files */
#include <ti/drivers/PIN.h>
#include <ti/drivers/pin/PINCC26XX.h>

#include <driverlib/ioc.h>
#include <driverlib/timer.h>
#include <driverlib/prcm.h>

/* Example/Board Header files */
#include "Board.h"

/* Pin driver handles */
static PIN_Handle buttonPinHandle;
static PIN_Handle ledPinHandle;

static String errormsg;
static uint16_t errorcode;
/* Global memory storage for a PIN_Config table */
static PIN_State buttonPinState;
static PIN_State ledPinState;

void Edge_Isr(UArg x); //ISR


PIN_Config ledPinTable[] = {
    Board_LED1 | PIN_GPIO_OUTPUT_EN | PIN_GPIO_HIGH | PIN_PUSHPULL | PIN_DRVSTR_MAX,
    Board_LED2 | PIN_GPIO_OUTPUT_EN | PIN_GPIO_LOW  | PIN_PUSHPULL | PIN_DRVSTR_MAX,
#if defined(Board_LED3)
    Board_LED3 | PIN_GPIO_OUTPUT_EN | PIN_GPIO_HIGH | PIN_PUSHPULL | PIN_DRVSTR_MAX,
#endif
    PIN_TERMINATE
};

/*
 * Application button pin configuration table:
 *   - Buttons interrupts are configured to trigger on falling edge.
 *   - If the UP, DOWN, SELECT inputs are defined add them to the table.
 */
PIN_Config buttonPinTable[] = {
    Board_KEY_RIGHT  | PIN_INPUT_EN | PIN_PULLUP | PIN_IRQ_NEGEDGE,
    Board_KEY_LEFT   | PIN_INPUT_EN | PIN_PULLUP | PIN_IRQ_NEGEDGE,
    Board_LED4 | PIN_INPUT_EN | PIN_NOPULL | PIN_IRQ_POSEDGE, // make IOID6/LED4 pin an input(I've physically disconnected LED4 from IOID6)
#if defined(Board_LED3)
    Board_KEY_UP     | PIN_INPUT_EN | PIN_PULLUP | PIN_IRQ_NEGEDGE,
    Board_KEY_DOWN   | PIN_INPUT_EN | PIN_PULLUP | PIN_IRQ_NEGEDGE,
    Board_KEY_SELECT | PIN_INPUT_EN | PIN_PULLUP | PIN_IRQ_NEGEDGE,
#endif
    PIN_TERMINATE
};


int main(void)
{
    
    Hwi_Struct hwiStruct;
    Hwi_Params hwiParams;
    xdc_runtime_Error_Block eb;
	
    /* Call board init functions */
    Board_initGeneral();

    /* Open LED pins */
    ledPinHandle = PIN_open(&ledPinState, ledPinTable);
    if(!ledPinHandle) {
        System_abort("Error initializing board LED pins\n");
    }

    buttonPinHandle = PIN_open(&buttonPinState, buttonPinTable);
    if(!buttonPinHandle) {
        System_abort("Error initializing button pins\n");
    }
	
	//setup the HWI
    Hwi_Params_init(&hwiParams);
    Error_init(&eb);
    Hwi_construct(&hwiStruct, INT_EDGE_DETECT, Edge_Isr, &hwiParams,&eb);
    errormsg = Error_getMsg(&eb);
    errorcode = Error_getCode(&eb);
    /* Start kernel. */
    BIOS_start();

    return (0);
}


void Edge_Isr(UArg x)
{  
  //never reaches breakpoints here!!!
  uint32_t currVal = 0;
  
  currVal = PIN_getOutputValue(Board_LED1);
  PIN_setOutputValue(ledPinHandle,Board_LED1,!currVal);
}