xlsx is crashed after upload but csv is fine
For xlsx file, after I upload, the file size increase from **16kb** to **24kb**, and pop up error when I try to open it
`Excel cannot open the file ’xxxx.xlsx’ because the file format or file extension is not valid. Verify that the file has not been corrupted and that the file extension matches the format of the file.`

For csv file, the file size does not change and csv files are able to be opened. 

Anyone has any thought?
