Replication system tables are located in the target database. Comprehensive information about replication errors is stored in the SYS_REPLICATION_ERRORS system table, see SYS_REPLICATION_ERRORS. For example:
solsql> SELECT subscription_id, error_time, error_code, error_text from SYS_REPLICATION_ERRORS;
SUBSCRIPTION_ID ERROR_TIME ERROR_CODE ERROR_TEXT
--------------- ---------- ---------- ----------
2 2018-04-20 10:41:25.0 26029 SOLID FEC Error 26029: Cannot read table TAB definition: table not found