missing files, installing Oracle DB 12c on Oracle Linux 7.2
The following is the excerpt of runInstaller.sh file


# Abort the install, if install/.oui file is not found in the stage area
#
if [ ! -f $CMDDIR/install/.oui ]
then
  echo "Source location is incomplete. Make sure you have downloaded and extracted
all the relevant archives."
        exit 1
fi

#



Which clearly states that if you are missing the .oui file it returns the given message.

Generally, after extracting the downloaded zip files manually we get two directories like database and database(0). The .oui file is hidden so we don't see it using general ls command and File Explorer. You can see it using ls -a command in Linux.

Solution:

Goto the second directory database(0)/install/ and copy the .oui file to the database/install directory.

[oracle@testsrv Desktop]$ cp 'database(0)'/install/.oui database/install