Libreoffice Math showing bizarre symbols

[Rob190]

I have a fairly old document with a number of matrix equations. When I opened it just now, the equations are not showing correctly. The source is:

M ^{-1} (tilde w - tilde w_0) = tilde m - bold 0T_P = left ( matrix{a # b ## c # d} right) cdot  left (matrix { x + x_0## y + y_0} right ) = left ( matrix{a # b ## c # d} right) cdot  left (matrix { x ## y } right ) + left ( matrix{a # b ## c # d} right) cdot  left (matrix { x_0## y_0} right ) = left ( matrix{a # b ## c # d} right) cdot  left (matrix { x ## y } right ) + left (matrix { x'_0## y'_0} right )

For some reason it now displays some rather strange symbols:

What do I need to do? Is there a legacy setting I can use? I have quite a lot of documents that use the maths editor.

Rob.

[anon73440385]

This seems to be a problem with the OpenSymbol font (did you delete that font?). What’s your operating system and LibreOffice version.

[Rob190]

Sorry should have added that:

Version: 6.4.6.2 (x64)
Build ID: 0ce51a4fd21bff07a5c061082cc82c5ed232f115
CPU threads: 4; OS: Windows 10.0 Build 19041; UI render: default; VCL: win;
Locale: en-GB (en_GB); UI-Language: en-GB
Calc: threaded

[Rob190]

I’d never heard of the OpenSymbol font but installing it has fixed the problem. Thanks!
How does it normally get installed? Would a windows or LO update uninstall it?

[erAck]

The OpenSymbol TrueType font is a dingbats font and provided with LibreOffice, using the Windows LibreOffice installer to repair the installation may had reinstalled it if something deleted it or the Windows registry was broken. The file name should be opens___.ttf wherever that installs to on a Windows system I don’t know.