In that case, I suggest you truncate the api_v3.log again [do not delete the file, only truncate, if you delete it, you’ll need to reload Apache before continuing] and re-run kaltura-sanity.sh with bash -x for more debug info, like so:
# bash -x /opt/kaltura/bin/kaltura-sanity.sh
This will output more debug info to STDERR, including the params passed to upload_test.php from the kaltura-sanity.sh shell wrapper. Then check the log for errors and try to understand why it fails.