The file system of Windows allows multiple processes to read and write the same file simultaneously. If necessary, the first process that has opened a file may prevent other processes from reading or writing it.
When archiving software tries to access and compress a file, if another process prevents the archiver from using the file, an error occurs and the compression cannot be made successfully.
Along with displaying the warning message as below, Bandizip provides a feature of compressing a file being used by another process if the file cannot be written but can be read.
If the feature is not needed, toggle off “Compress a file even when the file is used by another process” in the advanced settings as below.