You can't install Flash Player on a Galaxy S4. Android 4 is incompatible with Flash Player.
Android recommends using either "Dolphin" or "Puffin" browser to view content that requires Flash Player. They're both free in the GooglePlay store.
I have installed Dolphin .. went to >
Settings > Web content > Flash Player > Always On. Unfortunately I'm still
unable to play. Any suggestions?
sideload the flash apk and use the stock browser which supports flash. I highly recommend Ocean Browser for S4. Right after realising that stock browser does not support flash, I switched to use this great thing. read this step by step tutorial : Install Flash Player on Galaxy S4. Before this one was for tablets only (mostly Nexus 10 users) but now also for phones.