Hi All,

I have been getting this error for a while but I don't seem to find where the issue is coming from. 

Looked into multiple discussion threads but I could not find a lead. 
I am currently buying and selling securities using an SP500 universe using dropbox data. Any help would be really appreciated.

The security with symbol 'CVG RD6QFO3VZL2D' is marked as non-tradable.
The security with symbol 'GMCR R735QTJ8XC9X' is marked as non-tradable.
The security with symbol 'NYX TGSA236FGWO5' is marked as non-tradable.
The security with symbol 'APC R735QTJ8XC9X' is marked as non-tradable.
The security with symbol 'HSP SYCMR2MNWEHX' is marked as non-tradable.
The security with symbol 'AMCC R735QTJ8XC9X' is marked as non-tradable.
The security with symbol 'APCC R735QTJ8XC9X' is marked as non-tradable.
The security with symbol 'CELG R735QTJ8XC9X' is marked as non-tradable.
The security with symbol 'PSFT R735QTJ8XC9X' is marked as non-tradable.
The security with symbol 'ARG R735QTJ8XC9X' is marked as non-tradable.
The security with symbol 'SGP R735QTJ8XC9X' is marked as non-tradable.
 

Thanks,

Dario