机子上装的是step7 5.2,在打开一程序时,不能使用Go to location 命令,屏幕出现:Unable to find the reference data required for execution 确定后,会出现: There are no parameter and local variable names available because their description is not available or cannot be assigned. 但打开别的程序没有此现象,提示没用任何符号信息,已将符号表导入文件,还不可行,不知道是怎么回事!