Sandisk curzer blade 64 too slow and......

Sandisk curzer blade 64 too slow and…
I’m father has bought Sandisk cruzer blade 64 but it dosen’t work properly.

My sandisk is SDCZ50C-032G-B35B.

In device manage it shows :[generic usb mass storage]…not as before .
Also, I can’t transfer a 4GB or larger file to my USB flash drive.

Your firmware (SanDisk SecureAccess) dosen’t recodize my flash drive.

How to repair my flash drive ?
How to downlaod the right frameware ?

Not sure how many drives you are trying to fix, your father’s or your own.

Sounds like someone bought a used blade or formatted a new one.  New drives larger than 32 GB are formatted as exFAT which supports files larger than 4 GB, which is a FAT32 format limitation. 

SecureAccess only runs on SanDisk drives and only supports the drive it is on.

Firmware for Windows devices is gotten from Microsoft.  For other OSs I have no idea.