Creating charts with libreoffice for our older readings has been known to be an issue because there is a dot in the filenames.
To fix this, remove the . from near the end of the filename, and it will then work fine.
eg
"G4:FS0-2018-07-26 07:55:11.209310.csv"
becomes
"G4:FS0-2018-07-26 07:55:11.csv"
The format for future readings will change shortly to do this fix for us.
I've made this sticky for 2 weeks so hopefully everyone sees it.
Hamish
Creating charts from the older readings (.CSV) files
Re: Creating charts from the older readings (.CSV) files
This issue has been fixed in the latest development version of Libreoffice.
Hamish
Re: Creating charts from the older readings (.CSV) files
Good to know, thanks for the information.