Fess crawler lost(missing) files

(from github.com/minhtienhcmus)
Currently I use fess version 12.1
When I crawler, some files are crawled but not displayed when searching.
I saw [fess-crawler.log] but did not see anything
I do not know why
Can you help me explain this problem?
Thank you so much!!!

Below is a file not found when searching:
2018-10-04 02:50:49,872 [Crawler-PXtyPmYBBoKKj0VBTaDL-1-2] INFO Crawling URL: smb://192.168.1.62/Test/Testproject/構築_5/営業/構築_4/20171115_集計リスト.xlsx

file [fess-crawler.log]:
fess-crawler.log

(from github.com/marevol)
You can check indexed content in Admin Search page.

(from github.com/minhtienhcmus)
I had check in Admin Search page but Fess crawler also missing files

(from github.com/marevol)
You can check debug logs if changing logLevel to debug for Default Crawler in Scheduler.