It is very important for Nokia Suite to set the "Export All Information" file of SMS in NBU format. I changed it before, but now I can't change it back.

CSV is actually an abbreviation for comma-separated values. The file types displayed in File Explorer are separated by commas. According to the original settings of the computer, if you click the file directly, the computer will open the file in EXCEL mode. However, it is recommended that you never do this, because if you open a CSV file in EXCEL, the CRC value in the file will be saved as a scientific symbol due to the data conversion of the computer file, resulting in an error in the CRC value in the file. This is also a painful experience I got when I was a beginner, but if you want to see the true face of CSV file, I suggest you open it with a clipboard or notebook, then save it as a new file and open it with EXCEL, which is also one of the methods. The opened CSV file contains four or five fields (parts), which are recorded from left to right: file name (XXXX. JPG), file size (in bytes), CRC32 value (consisting of eight English letters or numbers), file path (the name of the subdirectory where the file is located) and file content description (usually the English name of the star or even the album name, or it may be blank). The fourth column "file path" usually does not exist, because everyone saves and organizes graphics files in different ways, but there are usually CSV files with the column "file path", also known as ECSV files.

You open it, save it in TXT format, and then convert it into EXCEL.