ORA-01536: space quota exceeded for tablespace 'LIST01'

Hello All,
I am new to this community.

I need your suggestion regarding error in alertlog file.
 
database version :10.2.0.4
ORA-01536: space quota exceeded for tablespace 'LIST01'

when i check with DBA_TS_QUOTAS for tablespace_name='LIST01'

tablespace_name     username                              bytes      max_bytes
LIST01                         SYS                                     0          -1

LIST01                        NOTEDEV                       19922944    -1

and also when i checked with DBA_DATA_FILES

TABLESPACE_NAME                     BYTES
------------------------------                       ----------
LIST01                                           104857600

bytes column display this much of bytes it is used...

i am bit confused about this bytes column and help me to solve the problem.

thank and regards,
Muhammed Thameem. S