Excel Office 365, to create an Array formula- "Ctrl-Shift-Enter" is not making the formula work

[wmichael]

Hello. In Excel Office 365, to create an Array formula- "Ctrl-Shift-Enter" is not making the formula work rather it produces the error code #VALUE ! - here is the formula- thank you in advance for your help on this.
=CONCATENATE(SUM(IF(FREQUENCY(IF(LEN(H2:H500)>0,MATCH(H2:H500,H2:H500,0),""),IF(LEN(H2:H500)>0,MATCH(H2:H500,H2:H500,0),""))>0,1))," STs in media area")