SanDisk cruzer Glide 64G disconnects on its own

Hello. My name is Serge

I always kept a copy of my folders (picture, excel, word files, etc etc) on a cruzer sandisk memory stick. 

I begun to get a problem recently when I tryied to make a entiere copy of all folders include on mySandisk. I wanted to get a miror of my sandisck. 

The transfert begun and after 5 or ten minutes, it stops. Nothing was possible. The cruzer was not visible on my cumputer, like if it disconnect by itself; fortuitous way, nothing was changed or something.

I removed and reconnect it. It’s reappeared and I was able to get acces at all his content! I can open the files but can not copy them in a bunch to an another drive.

This hapen every time now. Each time I try to copy a little bunch of files to or from my sandisk cruzer, it deassaper ou it disconnect so it’s not posssible to continu the prosesus.

I would love to rescue all my files to move them to another drive more reliable. I don’t care if I need to scrap that stick but want at least rescue my folder.

Someone can help me to fix it or understand what hapen?

Thank you very much,