Math (Formula Object) custom symbols causing Error

[ZJChow]

I am making custom symbols for use with Math formula object, and in my use-case specifically I was attempting to insert Ux01D4B5 found in Cambria Math, Mathematical Alphanumeric Symbol subset to depict a Z-transform. What I found was that by closing and reopening the document, or even just by working on the same document for a while (without closing), the error popup message “Error activating object: General OLE error” would ensue whenever attempting to edit the formula object.

This appears to only affect letter-like symbols in “Mathematical Alphanumeric Symbol”. I have also attempted to replicate this using another font DejaVu Math TeX Gyre with this symbol subset, and I would encounter the same issue. I’ve had no issues with other symbols such as math operators, arrows etc. for dozens of documents i’ve created in the past. Edit: discovered that I previously used a custom “Mathematical Alphanumeric Symbol” and had no issues back then. This was probably from an early 2022 Libreoffice version. This symbol is now malfunctioning as described above.

I also noticed that when editing the affected symbol (select formula object > Tools > Symbols > Edit) the before and after image on the bottom right side would show some sort of hangul character, which is a tell-tale sign. The font subset also appears to be wrong, somehow. Unaffected symbols will only have the same before and after image when first entering the edit symbol dialog.

It wouldn’t be so bad if only that single formula object was affected, but earlier it it had catastrophically corrupted an entire document worth of formulas, causing even formulas without custom symbols to popup the error message, and some would display the dreaded blue jigsaw over the entire object.

Would like to ask if anyone else can replicate this, and if it should be moved to bug reports?
Version: 7.5.0 (first appeared), 7.6.2 (still occurring after reinstall)
System: Win11

[ajlittoz]

Instead of modifying the symbol table, why don’t you enter explicitly your character?

Type “U+1b4b5” (without quotes) followed by Alt+X anywhere you need it.

U+<hexa_code> is a universal trick in any LO component to enter a Unicode character when it is not otherwise readily available. It works also in Math.

Does this solve this issue (which may be related to symbol table patching)? Since Math development lags light years behind the other components, it may have problems with characters outside the Basic Multilingual Plane. U+D4B5 is precisely in the Hangul Syllables block and looks like the glyph in your screenshot. I highly suspect truncature to 16 bits. And who knows what happened to the upper 16 bits. If they are stored, they may have erased some technical control data, explaining the error.

[ZJChow]

Many thanks for the reply. Unfortunately, when following your suggestion in Math only a square shows up which means that the desired symbol isn’t appearing. Furthermore, this would not be a very sustainable method, as I would have to remember the unicode instead of mapping it to some convenient syntax such as %mathz.

I suppose something did break in-between the new LO updates, since it seemed to work about a year ago. Quite a pity to hear about the slow development for Math, I actually prefer the most of the LO typesetting syntax over LaTeX. Guess I’ll have to settle for using standard letters for now.

[ajlittoz]

If you get an empty square, the requested glyph is not present in the selected font. So, retry by forcing a font. You can do this with operator font. Look for details in built-in help.

My configuration is Fedora 39 (Linux) under KDE Plasma desktop, LO 7.6.2.1. I suppose the font renderer found automatically a suitable font face containing the glyph.

If you have a smart clipboard manager, you can record the encoding and paste it by selecting the entry.

In case my guess about truncation/overwrite is correct, restart in safe mode to see if things improve (assuming the symbol table is saved in the user profile). If so, you’ll have to reset your user profile.

[cwolan]

A note on error(s).
Two tests on Windows 11 with versions: 7.3.7.2, 7.4.7.2, 7.5.8.2 and 7.6.2.1

(1)
The symbol “mathz” defined in Math as Ux01D4B5 (Cambria Math font) and
inserted into a Math document. Saving the document only works with version 7.3.7.2, in other versions one sees an error message.

(2)
Writer document, inserted math object “mathz”, document saved and reloaded.
Attempting to edit the object only succeeds with 7.3.7.2., otherwise LO displays an error message.

Both animations recorded in 7.5.8.2