Description:
Most of the time, writer opens normally but when it comes to saving, it just produces a window with general input/output error and won't save. The file is left untouched, but no error message is given (when starting writer from console), even in --safe-mode.
For at least one of my files, writer won't open : a window shortly appears and then closes. There is no error message on console either, even in --safe-mode.

Steps to Reproduce:
1.libreoffice --writer --safe-mode doc.odt
2.
3.

Actual Results:
a window shortly appears and then closes
no error message on console but a lockfile is created and not cleaned up after closing.
alternatively writer opens normally but when I try to save, a window opens with "general input/output error" and I cannot save. I then close the error window and the file (without saving). A lockfile is created and not cleaned up after closing.

Expected Results:
In the first event, it should have opened the file !
On the second event, it should have saved my work !


Reproducible: Always


User Profile Reset: Yes

Additional Info:
My system is Archlinux and I upgraded from 7.6.6.4 to 7.6.7.1 a few weeks ago and I guess the bug started at the same time, though I cannot be completely sure of it.
I simultaneously upgraded libreoffice-still-fr. 
I upgrade my system using Octopi.
There is another bug, this time with calc. It works globally normally, though at start-up a window appears telling some attributes can't be read. Nevertheless I can work and save normally.