BUG: Error in SHOW OBJECT Syntax Causes Lockup

• Microsoft FoxPro for Windows, versions 2.6x
• Microsoft FoxPro for MS-DOS, versions 2.6x

SYMPTOMS

An error in the syntax of a SHOW OBJECT command will cause the machine to lock up immediately.

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Steps to Reproduce Behavior

WARNING: The following code will lock up your computer. Unsaved information in open applications will be lost. Before executing the following code, close all applications except Microsoft FoxPro.

1. Build a screen with 2 push buttons (mpush1 and mpush2).

2. In the VALID clause for the mpush1 button, place this code:

   SHOW OBJECT OBJNUM(mpush1,1) PROMPT 'Okay'

3. In the valid clause for the mpush2 button, place this code:

   SHOW OBJECT (mpush2,1) PROMPT 'Lockup'

   NOTE: The OBJNUM function is intentionally missing from the VALID clause.

4. Generate and save the screen.

5. Run the screen and push the mpush1 button. The prompt should change to Okay.

6. Push the mpush2 button and the machine will lock up. Attempting to break out of the lockup by pressing CTRL+ALT+DEL causes the system to drop to an MS-DOS screen, and give this message:

         EMM386 has detected error #06 in an application at memory address
         00B8:0B57. To minimize the chance of data loss, EMM386 has halted
         your computer.
   

         For more information, see the README.TXT file.
   

         To restart your computer, press ENTER.