There is a known issue that exists with files zipped using OSX (Mac) that are above a 4GB file size which makes them unopenable on other operating systems. This is usually only discovered when the recipient of the zipped file attempts to unzip it. In fact it can even occur on OSX when using tools other than the inbuilt Mac unzipping tool.
This issue interferes with GoldFynch as well. If you or your clients use OSX, you will need to do one of the following:
- ensure the size of ZIP files uploaded are lower than 4GB (using a split zipped archive may help with this)
- Create the ZIP file on a different operating system like Windows 10
- Use software that specifically supports this, like 7-zip (refer to this)
If you would like to learn more about this issue, you can find it discussed in greater depth on web forums like these: