java.lang.IllegalArgumentException: java.lang.IllegalArgumentException: field [content] not present as part of path [attachment.content] with large pdf files

php occ fulltextsearch:index stops indexing at pdf files with

Exception: Elasticsearch\Common\Exceptions\ServerErrorResponseException
│ Message: java.lang.IllegalArgumentException: java.lang.IllegalArgumentException: field [content] not present as part of path [attachment.content]

I deleted the first pdf where indexing stopped, started the indexing command again. fulltextsearch indexing stalled again on a pdf file. And again after deleting this one too.

Common pattern: all pdf files were larger than 70 Mbyte.

Elasticsearch is running with 8 GB of RAM:

Active: active (running) since Mon 2018-10-08 16:14:13 CEST; 1h 10min ago
Docs: http://www.elastic.co
Main PID: 504 (java)
CGroup: /system.slice/elasticsearch.service
|-504 /bin/java -Xms8g -Xmx8g -XX:+UseConcMarkSweepGC -XX:CMSInitiatingOccupancyFraction=75 -XX:+UseCMSInitiatingOccupancyOnly -XX:+AlwaysPreTouch -Xss1m -Djava...
`-807 /usr/share/elasticsearch/modules/x-pack-ml/platform/linux-x86_64/bin/controller

Latest apps installed (1.01) and configured.

Any hints on this? I would love to use fulltextsearch on my files...

Start by reproducing php occ fulltextsearch:index with a PDF larger than 70 MB and inspect the reported Elasticsearch exception. Compare indexing behavior before and after the large PDF. Done means indexing continues without the missing attachment.content field error and subsequent PDFs are indexed.