NetScaler appliance with fiber SFP FTLF8519P3BNL has "Unsupported SFP" message in the log file.
The issue has been fixed in NetScaler 10.1 130.x and NetScaler 10.5-53.x.
For NetScaler platforms running 9.3 builds and builds older than 10.1.130.x & 10.5.53.x, the log file shows that these SFPs are unsupported. However, these SFPs function properly without any issues.