In double entry accounting, errors are not a problem because they are self correction, is it true ?

Yes, it is,,We can do by using the formula VB or macros, or by using the main functions of the IF and VLOOKUP.

In Double Entry System we have Double aspects of every transaction. 

1. Debit

2. Credit.

If any transaction recorded wrong how could Double entry system Rectified it self.

So it's not true.

No, I disagree with you although it will not have any impact on your trial balance but that will adversely or unduly show a wrong picture to the users.