If we speak in general, then most local scholarship committees are not concerned with minor mistakes  but as far as the higher level of competition is concerned, even a single mistake can ruin the form...

Even small spelling mistakes can result in ruining an application and can lead to the application form being thrown out. I would like to give you an example. In one of the forms, a boy on the baseball team wrote that he won the league batting title with a .259 average. It was the biggest error as most likely, the no. 2 should have been a 3, 4, 5, or even 6.
Yet, in another application form, the age was listed as "88." And it was believed that she was the oldest high school student in the country...or perhaps in the whole universe? But wait, there is one more thing... she listed her date of birth as eighteen years earlier. These are the kinds of those stupid silly mistakes that can disqualify good candidates. It is recommended that one should always make use of SPELL CHECK and have someone read for context and spelling problems. Most people cannot do a perfect job of proof-reading themselves... it is a fact...

one of the most common mistakes is leaving blank spaces. This is not a good thing. Others may think that you are trying to hide or close something. If something is not of your relevance, write DNA on the line, which is the standard abbreviation for Does Not Apply, rather than leaving blank space.

Make use of spell-check or keyboard whenever possible. Investigate all kinds of free form-filling computer programs. No long hand here. One should never write in pencil. And, NEVER, NEVER. EVER, EVER use fluid or whitener.

Follow directions exactly. Sometimes a signature is needed with the name printed. A simple YES or NO may be necessary, rather than giving a full-fledged paragraph of your opinions.

It is often seen that after spending half of the lifetime in school, people still have problems using to, too, two, and they're, their,there.

Check, Check, Check. Always check the form three times before handing it over to the committee...

What can you do, if a particular kind of error cannot be corrected? Be sure to make a copy before you start. If the document says "copies are not permitted," then there are no options left but to go back for one or two more originals.