How to set sampling for lots of files with short texts?

[fishfree]

I have a corpus of 2550 Chinese files, of which each file only contains about 5+ words, for example: 补天 济时 ， 勿 认真 作 常言 。
If I don't set sampling, so many files cause sticking together as the screenshot below:

If I set sampling as below:

and other settings are as below:



It always reported error as below (even I set the sample size as 1):

> stylo()
using current directory...
Performing sampling (using sample size = 5 words)

slicing input text into tokens...

Error in make.samples(loaded.corpus, sample.size, sampling, sample.overlap) : 
  Corpus error...
In addition: Warning message:
In make.samples(loaded.corpus, sample.size, sampling, sample.overlap) : 

补天济时勿认真作常言...	This text is too short!

I noticed the text 补天济时勿认真作常言 in the error info deleted spaces in my provided text.