ERROR OGG-01496 restarting extract

Question

Each time i restart the extract process after a normal stop i got this type of error:
ERROR OGG-01496 Oracle GoldenGate Capture for Oracle, EXT1.prm: Failed to open target trail file P:\OracleGoldenGate\dirdat\lt000661, at RBA 5466894.
Why and what can i do? No i delete the ext1 group and then i create the same group again...
The extract group parameter file named ext1 is:
extract ext1
userid ggschema, password ggschema
rmthost 192.168.2.225, mgrport 7809
exttrail P:\OracleGoldenGate\dirdat\lt
rmttrail P:\OracleGoldenGate\dirdat\lt
ddl include mapped objname TESEO2.* ;
TABLEEXCLUDE TESEO2.AGGANCI_ALL_MV ;
TABLEEXCLUDE TESEO2.ESTREMI_RN_RISOLTI_MV ;
TABLEEXCLUDE TESEO2.ESTREMI_UDOC_MV ;
TABLEEXCLUDE TESEO2.MASS_CLASS_MV ;
TABLEEXCLUDE TESEO2.NOTEDOTT_CLASS_MV ;
TABLEEXCLUDE TESEO2.NOTE_MV ;
TABLEEXCLUDE TESEO2.CORRELAZIONI ;
TABLE TESEO2.* ;
The manager param is:
GGSCI (dbgen) 43> show param mgr
Parameter settings:
SET SUBDIRS ON
SET DEBUG OFF
Current directory: P:\OracleGoldenGate
Using subdirectories for all process files
Editor: notepad
Reports (.rpt) P:\OracleGoldenGate\dirrpt
Parameters (.prm) P:\OracleGoldenGate\dirprm
Replicat Checkpoints (.cpr) P:\OracleGoldenGate\dirchk
Extract Checkpoints (.cpe) P:\OracleGoldenGate\dirchk
Process Status (.pcs) P:\OracleGoldenGate\dirpcs
SQL Scripts (.sql) P:\OracleGoldenGate\dirsql
Database Definitions (.def) P:\OracleGoldenGate\dirdef

Answer 1

what kind retention policies do you have for trail files. As per the error, GG is not able to open the file "P:\OracleGoldenGate\dirdat\lt000661".
Ideally you need to find the root cause but in the mean time you can issue "alter extract <name> etrollover" and start the extract.