WinRAR decompression prompt CRC error resolution

WinRAR can be said to be the most beautiful compression software now, the limelight gradually overshadowed the old WinZip! Super high compression ratio, easy to use interface, powerful features...... But I don't know if you have ever encountered such a situation: I have painstakingly downloaded hundreds of megabytes of RAR archives from the Internet. When I unpack it, I suddenly pop up a dialog box that will make you feel scared! Tell you that something went wrong...

First, determine the cause of the error

The error message is "CRC failed in encrypted file (password error?)" (RAR compression has a password, but the password is entered incorrectly or the password is entered correctly but cyclically redundant Check code (CRC) error! Just because the RAR compression package adds a password, WRAR guesses that it may be "password error")

The method of distinguishing the above two errors: If the password is entered If you have a mistake, you can't extract any files! But if there are multiple files in the compressed package and some files are decompressed, it should be a RAR compressed packet cyclic redundancy check (CRC) error instead of password input. Error.

Cyclic Redundancy Check Code (CRC) error, this is the most common situation, which is the focus of this article! Different from the above several decompression errors, this situation is damaged with RAR compression package related.

There are several reasons:

(1) The network transmission status is not good (such as too many disconnections, too many threads open, too many server people can not connect too much, etc.) The downloaded file is corrupted!

(2) The RAR archive provided by the site is inherently corrupt (this is no way, unless the archive contains a reply record).

(3) The downloading tool used is not perfect. For example, some downloading tools open several threads, the downloading work is very slow, and sometimes the data is not transmitted when downloaded to 99%. , must be manually operated to end (stop downloading and then start). I have encountered this situation several times. The result is a CRC error after the file is downloaded and decompressed to the end.

Secondary, emergency solution

1.Using recovery records

There is a condition to repair the CRC. It must be a recovery record in this RAR archive. The record is an option when the RAR archive is compressed.

When WinRAR compression, the recovery record is not placed by default. If the RAR compression package is provided, it is impossible for the user to fix the CRC error.

2. Bottom pumping

If the files in the RAR archive are the same or even normal use even if the file is missing (in fact, most files are not damaged by partial data) Very sensitive), then we can make our ultimate killing trick: the bottom of the pumping method!

The principle is to decompress the damaged files in the RAR compression package, ignore the warning of WinRAR, how much can be decompressed How much is decompressed. The decompression software still uses WinRAR, but do a small setup.

In the window that pops up after right-clicking on the extracted file, select the "Keep damaged files" checkbox and click OK to start decompression. Don't bother to unpack the error message. After the decompression ends, you will find that the corrupted file is unzipped. The chances of a damaged file being decompressed in this way are still very high.

Three, do a good job of insurance

1. Make a recovery record

The original RAR compression package is compressed, if you choose to place the recovery record, so that even after the user downloads the CRC Errors also have the opportunity to repair themselves!

2. Take the volume compression

The method of volume compression can greatly reduce the loss caused by unrecoverable errors.

3. Old files are also added to the recovery record

Someone may ask, the new compressed RAR compression package can be added to the recovery record, then the compressed RAR package has no way plus recovery Recording? There is a way to add a recovery record to the already compressed RAR archive.

Just open the zip file and select "Protect Archive" from the "Command" menu.

Four, small common sense:

In fact, the solution to the RAR compression package error is mainly based on prevention! If there is no prevention, if there is a real problem, there is no way to solve the problem perfectly. In the case of a cyclic redundancy check code (CRC) error, if the RAR archive does not contain a recovery record, it is impossible for the user to fix the CRC himself! The main purpose of this article is to tell you some reasons for the error and Discuss some ways to prevent mistakes fundamentally and minimize losses!