Error when I click on the Crawler Progress Summary

Question

When I click on the Crawler Progress Summary button when the Primary Schedule is in the status of "executing"
I get the error:
Oracle Ultra Search Error
ORA-20000: Oracle Ultra Search error
ORA-01843: not a valid month
ORA-06512: at "WKSYS.WK_ERR", line 179
ORA-06512: at line 1
if I click on the Crawler Progress Summary button when the Primary Schedule is in the status of "scheduled"
I get the error:
Oracle Ultra Search Error
Failed to retrieve past statistics. Crawler may have been shutdown unexpectedly.
Can anyone assist please?
Thanks in advance, Sarah
ps
In the logs I get the results:
=================== Crawling results ===================
Crawling stopped at 20/05/02 14:45
Total crawling time = 0:0:35
Total number of documents fetched = 71
Total number of documents updated = 70
Total number of documents deleted = 1
Total number of unique documents indexed = 64
Total data collected = 678,608 bytes
Average size of fetched document = 10,603 bytes
Total indexing time = 0:0:2 for 678,608 bytes of data

Answer 1

The crawler log file should have a bit more information on this "ORA-01843: not a valid month" error.
Without looking into the log file my guess would be one of the URLs crawled contain an invalid timestamp string which
cause an insertion error as oracle expected the date information to be in some format.
Did the crawler shut down before finished crawling? Check the log file to see if the URL queue size is 0 before it terminates.
If not then the crawler shutdown because of this ORA-01843 error.
Because the statistics is reported by the crawler when it terminate normally, there will be no statistic data if it is a
first time crawl and the crawler terminate due to the above error.