Why does the Quartus® II software freeze when I add a signal to the SignalTap II Logic Analyzer? - Why does the Quartus® II software freeze when I add a signal to the SignalTap II Logic Analyzer? Description Due to a problem in the Quartus® II software version 12.0 SP2 and earlier, the Quartus II GUI may freeze when adding signals in the SignalTap™ II Logic Analyzer if your quartus2.qreg file contains an invalid statement. Resolution To work around this problem, open quartus2.qreg and remove any lines that contain the text "Node_finder". The quartus2.qreg file can be found in the following location: Windows 7: C:\users\ <username> Windows XP: C:\Documents and Settings\ <username> Linux: ~/.altera.quartus This problem is fixed beginning with the Quartus II software version 12.1. Custom Fields values: ['novalue'] Troubleshooting novalue False ['novalue'] ['FPGA Dev Tools Quartus II Software'] 12.1 11.1 ['Programmable Logic Devices'] ['novalue'] ['novalue'] ['novalue']