System Console Oscilloscope function does not aleays work with NIOS

I am doing data acquisition using the ADC in the MAX 10. I am trying to us the oscilloscope function of the System Console to monitor the ADC inputs.

When I am using it without the NIOS it works fine. When I install the NIOS Processor and call System Console from Eclipse it will work occasionally but usually I get the following error messages:

master_write_32: java.lang.NullPointerException

while executing

"master_write_32 $sequencer_service 0x0 1

"

(procedure "::adc_toolkit::trigger_sample_trace" line 39)

invoked from within

"::adc_toolkit::trigger_sample_trace $channel_number $sample_size"

(procedure "::adc_toolkit::trigger_sample" line 3)

invoked from within

"::adc_toolkit::trigger_sample $channel_number $sample_size

"

(procedure "::adc_toolkit::scope_test" line 28)

invoked from within

"::adc_toolkit::scope_test"

("uplevel" body line 1)

invoked from within

"uplevel 1 $command_string

"

(procedure "::adc_toolkit::debug_timer_run" line 7)

invoked from within

"::adc_toolkit::debug_timer_run ::adc_toolkit::scope_test {scope test}"

("after" script)

Any idea why it sometimes works and sometimes fails?

I am using Quartus Version 15