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AR# 36813

13.2 Project Navigator - "A Xilinx Application has encountered an unexpected error" when 2-byte characters used in HDL code


If an HDL source file in an ISE project contains 2-byte characters outside a commented section, Project Navigator crashes with a pop-up window stating the following errorand there is a line of "Null Null Null..." in the Console.

"A Xilinx Application has encountered an unexpected error. It is recommended that you save any unsaved work in the event that this condition persists. For further assistance, please consult the Answers Database and other online resources at http://support.xilinx.com"

In most cases, closing ISE and opening it again does not help because the previous project is opened by default. How can I resolve this problem?


This crash can be caused by any 2-byte (unicode) characters in the HDL code which exist outside of user comments (typically entered or un-commented by mistake).

Example 2-byte characters include:

--Asian punctuation (such as semicolon, space, colon and so on typed in using Chinese, Japanese, Korean or other Asian input method)
--Asian characters
--German characters such as umlauts

As long as the 2-byte space is enclosed in a commented section of code, there should not be any problem with it, but the compiler does not know how to handle it outside of a comment.

To avoid this problem, make sure that punctuation is typed in with English input method and properly comment user notes and documentation.

To resolve the problem after the crash has occurred, close Project Navigator, remove the HDL file or project or move it to another location, and then open Project Navigator again. Edit the HDL source to remove offending characters before adding to project again.

This issue was fixed in ISE Design Suite 12.2, but was inadvertently introduced again due to a late change in ISE Design Suite 13.1. The issue is scheduled to be resolved in ISE Design Suite 13.3. However, 2-byte characters will still result in syntax errors if they are found outside commented sections of code.

Linked Answer Records

Associated Answer Records

Answer Number Answer Title Version Found Version Resolved
34244 ISE - HDL Source file with Japanese comments fails synthesis with HDLCompilers error N/A N/A
AR# 36813
Date Created 10/14/2010
Last Updated 05/19/2012
Status Active
Type Known Issues
  • ISE Design Suite - 12.1
  • ISE Design Suite - 13.1
  • ISE Design Suite - 13.2