French spell check Librewite

I’m running Libreoffice writer 5.1.6.2. I need to write letters in French occasionally and before when I was dual booting this computer with Windows 10 and Ubuntu 16.04 had no problems with the spell check in French. Now however I have had no luck.

French has been installed from Language support.

I have downloaded ( 5 times) Language Tool 3.7 and Dictionnaire Française 5.7. I have selected French spelling dictionaries from the language tool drop down and chosen the recommended version.

I have reloaded Librewrite after each change and even rebooted the laptop.

I set my default language to French (France) with the “This document only” box ticked. Also, I change language on the dialogue below the document to French.

I have run the myspell to load the French file.

Yet when I type in French every word is underlined as an error, even the simple words such as “Je suis ...” etc., Setting spell check to auto does the same. However, when I call up spell check with the F7 key I am offered a long string of mixed characters some even Greek letters.

Even changing the paragraph style to French makes no difference. I worked through an excellent and very detailed step by step check on the OO website and all answers were YES right to the end, until I downloaded the check file, which just did not work as suggested.

Obviously I’m making mistakes or missing something, but just what I cannot think. I used the set up with 14.04 on another computer with no problems and as I said on this machine when a dual boot.

My spoken French is quite good, but I need the spell check when writing.

If anyone can help or direct me to what else to try I would be most grateful.

I could not find any other answers here, but maybe I'm missing those also, if so I apologize.

Hal.