[Bug]: "NoneType" object has no attribute "strip"

[Shukino20001015]

Is there an existing issue for the same bug?

• [x] I have checked the existing issues.

RAGFlow workspace code commit ID

d197f33646a1ae517c5c017b18e18a510f2d7ee1

RAGFlow image version

infiniflow/ragflow:v0.16.0

Other environment information

ubuntu 22.04 LTS

Actual behavior

我在初次建立知识库，用了以下配置参数，对中文pdf进行索引，连续两次产生这个报错，请问是什么原因导致的？

Expected behavior

No response

Steps to reproduce

中文pdf 链接到知识库能正常分chunk ，就产生了这个报错

Additional information

No response