If Sony alters their support pages, community-vetted mirrors like PlayStation Update Archives or the Brewster console archive preserve the exact, unedited bytes of the original PUP file. Verifying File Integrity
Save the downloaded file as PSVUPDAT.PUP in the UPDATE folder. ps vita 374 firmware link
Unlike the later PS3 updates, the PS Vita scene has a persistent exploit called h-encore² . This works perfectly on 3.74. If Sony alters their support pages, community-vetted mirrors
Cause: The PUP file is corrupted or for the wrong region. Fix: Re-download the file from the official Sony link above and ensure your internet connection did not drop. If Sony alters their support pages