Could you please put a screenshot?
Normally it's in the framework of the Property manager
Namely everything before <DIM> in the menu on the left of your quote
I would like this botation to no longer appear in the sketches or in the plans without being obliged to do it on each side requested
sw.png
Hello
If my memory serves me correctly, this problem is related to a loss of the parameters of Solidworks which must interpret this famous <Mod-Diam> as Ø on display. It seems to me that there is already a topic on this forum (or on another one that deals with this problem)
Edit: at minma I found this: http://www.lynkoa.com/store/fr/le-symbole-de-diametre-n-est-plus-visible-sur-mes-cotations-le-texte-mod-diam-apparait-a-la-place.html
Edit2: My memory doesn't fail: http://www.forum-cao-3d.fr/solidworks-mise-en-plan/cotation-mod-diam-t7895.html
Conclusion, contact the hotline to intervene on the basis of the register.
To complete Cyril.f's answer
http://www.forum-cao-3d.fr/solidworks-mise-en-plan/cotation-mod-diam-t7895.html#p117422
Quote from judi
So I went to "System Options", "File Location", and "Symbol Library Files".
In my case, I had to change the location "C:\ProgramData\SolidWorks\SolidWorks 2014\lang\english" to "C:\ProgramData\SolidWorks\SolidWorks 2015\lang\english". And it works properly again!!