Impress - write error

When I am trying to save my presentation at Impress, is showing the following:

Error saving the document: Write Error. The file could not be written.

How can I fix it please?
Thank you!

I have exactly the same issue with Draw, while trying to save a very simple drawing. Would it be possible to have some assistance ? Thanks in advance.

It will be difficult to communicate about this bug as I cannot save the document to forward it to whom could ask for it. The process to make it was as follows : open a new drawing, write with the pencil several free form (a few hand written letters), group them, change the color and the size of the lines of the group (all at once) and then trial to save.

LO - Ubuntu 18.04