I am a total noob at linux but managed to do the following:

1. downloaded bash-4.1.tar.gz and placed in the root directory
2. tar -xzf bash4.1.tar.gz
  cd bash-4.1
  ./configure
  make
  sudo make install

3. I then rebooted my box and bash --version It now says version 4.1.0(1)-release (i686-pc-linux-gnu)

However I still get the error when running .sh file
Processing Node Number: 2000 - Callsign: WB6NIL
,/test.sh: line 43: ${f2,,}: bad substitution


Any thoughts?