Created attachment 57143 [details]
Screenshot of the problem.
When typing a formula, math symbols + - = etc. are typed in Wingdings font.
Trying to change fonts in math editor do not solve this problem.
Correspondingly, Wingdings Font is also used by default for bullets in text editor.
Solved by installing font opens___.ttf in windows font directory.
Thanks for additional testing
Due to last comment, changing status to WorksForMe
(in 3.5.3 on Windows 7 also works correctly by default)
If problem will appear again, please, change status to Reopened