“If you shut your door to all errors, truth will be shut out.”

i think that it means, that you can never learn from you mistakes, and that when you hide all your mistakes the truth will never come out and you'll be a fake.

learning from our errors is a very powerful tool

If you are afraid to make a mistake, you lose the opportunity to grow and therefore to gain truth.

Truth comes from being open minded and then weaning out or sifting out the false. The truth just like the cream comes to the top. Closed minded or ridge or radicalized personalities, that grasp tightly at a straw, politcal view, or mantra lose their abiltiy to see truth.

Indeed! You can't have one without the other...

Ah, yes, 'truth.' Always ever present and yet seems to elude us. There is no learning without making mistakes.