[Tails-dev] No possible to install Tails 4.20 on usb sticks

Dear Sirs,

    I've tried many times to install Tails 4.20 on two different usb
sticks (a 32GB one and a 16GB the other) and using two different
computers.The results were always that at the end of procedures the usb
sticks looked to have become 1GB only and their file systems RAW
type.The sticks became unusable.I had to use a terminal to format and
reset them.It was absolutely not possible to install Tails 4.20.I hadn't
ever had a problem like this,before.

    What to do,could you send me the previous Tails version or give  me
special tips to resolve the issue? My best regards.A.C.