OpenType Designer Cannot Reopen After Loading ~1,600 Two-Letter Words in Preview Pane

[faisal.quadirey]

OpenType Designer fails to reopen after adding ~1,600 words to Preview Pane — “A call to an OS function failed.”

Issue Detail:

I have encountered a reproducible problem in FontCreator 16.0.0.3077 involving the Preview Pane of the OpenType Designer.

I am working with a large set of approximately 1,600 words, where all of the words consist of two-letter words. When I add this large number of words to the OpenType Designer’s Preview Pane, FontCreator initially allows the data to be loaded/displayed.

However, after I close the OpenType Designer, I am no longer able to open the OpenType Designer again for that font/project.

When attempting to reopen it, FontCreator displays the following error:

“A call to an OS function failed.”

The OpenType Designer then fails to open.

This appears to leave the OpenType Designer in a persistent broken state for the affected font/project. Simply closing and reopening the OpenType Designer does not resolve the problem.

Expected Result

The OpenType Designer should either:

• successfully handle the large Preview Pane word list, or
• gracefully reject/limit an excessively large input,
• display a meaningful application-level warning if the input exceeds a supported limit,
• and, most importantly, remain recoverable after the OpenType Designer is closed.

A large Preview Pane dataset should not permanently prevent the OpenType Designer from being opened again.

I would particularly like to know whether FontCreator stores the Preview Pane word list or its state in the font/project configuration.

If so, the large word list may be causing an invalid or excessively large persisted state that FontCreator attempts to restore when reopening the OpenType Designer.

Could you please advise:

1. Is there a documented maximum number of words/characters supported in the OpenType Designer Preview Pane?
2. Is approximately 1,600 words expected to be supported?
3. Is there a known limitation with very large Preview Pane datasets?
4. Why does closing the OpenType Designer cause it to become unable to reopen?
5. Is there a way to reset/clear the Preview Pane data or configuration externally so that I can recover the affected font/project without losing my font work?
6. Does FontCreator have a log, diagnostic file, or crash/error report that I can provide to help identify the underlying OS-function failure?
7. Could this be related to a Windows resource limitation, Preview Pane buffer, persisted UI state, or another internal limitation?

Additional Information

The words are not unusually long. The significant factor appears to be the number of words in the Preview Pane, rather than the complexity or length of individual words.

The problem is particularly important for my workflow because I am working with large Arabic/Urdu/Qur’an-related word datasets and need to test OpenType shaping behavior against substantial word lists. Therefore, using only a small number of test words is not sufficient for my intended testing.

I have attached a screenshot showing the error dialog.

Product: High-Logic FontCreator v16.0.0.3077
Component: OpenType Designer → Preview Pane
Issue Type: Crash / persistent OpenType Designer startup failure
Operating System: Windows 11

[ErwinDenissen]

I don’t know why it becomes unstable.

It would help if I can reproduce it on my suystem, so can you provide:

• The font
• The text you used in the Preview

Send both to:
[email protected]

[faisal.quadirey]

please check email sent with font project file and text file containing words list for testing

[ErwinDenissen]

Thank you for sending the additional information. It helped me reproduce the issue. The problem will be fixed with the next upcoming release.

[ErwinDenissen]

Here is an update that should solve this problem:
https://high-logic.com/tmp/fontcreator/FontCreatorSetup16.0.0.3079.exe

Other changes and improvements:
Added

• Round Corners: new outline transform that replaces sharp corners with circular fillets (Transform wizard on both platforms; Glyph menu command on Windows).
• Set Anchors: add relevant anchors to a glyph (Recalculate Anchors forces default positions)

Changed

• Tools menu: Import Artwork renamed to Import Image…, matching the command’s name everywhere else.

Fixed

• Crash when dragging a variation slider with an element selected in a glyph whose masters don’t interpolate.
• Crash on macOS when the mouse moved after closing a dialog (stale tooltip reference).
• Crash opening the OpenType Designer on a font with a very long preview text (Windows).
• Typing an anchor’s X/Y position in the glyph editor’s context panel works on Windows — repaints no longer overwrite it, and Enter applies it.
• Copying and pasting a glyph keeps its components and live strokes instead of decomposing them.
• Pasted glyphs are matched by name, so editing the font after copying no longer pastes the wrong glyph.
• macOS dark mode: outline thumbnails in the Masters and Layers panel are no longer invisible black.

[Bhikkhu_Pesala]

I see an error message: “You do not have permission to access this document.”

I am logged in.

[ErwinDenissen]

It should now be available again.

[Bhikkhu_Pesala]

Downloaded and Installed OK

[277967435 (Liu)]

Thank you very much. I never expected the rounded corner function to be available so soon. After testing it, it’s quite good and supports variable fonts. However, there’s still a minor issue: after rounding the corners, the curve is not smooth and there will be bumps, as shown in the figure. I hope this can be improved. Thank you for bringing this new feature.

Adding rounded corners to variable fonts may significantly increase the file size, from 30MB to 130MB. Some software may fail to open such font files, or even crash. Is there a way to reduce the file size of rounded-corner fonts?

[faisal.quadirey]

download link is not working

[ErwinDenissen]

We have restored it. Can you try again?

[ErwinDenissen]

Do send me a sample project with specific glyphs that have issues and I will look into it.

The file size wil grown because of the added nodes. Not much we can do about it.

[faisal.quadirey]

downloaded and worked thanks.

[277967435 (Liu)]

host mail.high-logic.com[57.129.85.237] said: 552 Data size must not exceed 10000K bytes. (in reply to EHLO command)

The file is too large for your server to receive!

[277967435 (Liu)]

Sorry, the email was not sent. The attachment has been uploaded. Please check the source file, which may help you find the problem more quickly. Thank you!
Source file.7z (3.5 MB)

Also, you can use this font test. The outline script is unavailable. Thank you very much.

[ErwinDenissen]

The Transform feature should be available since the last release.

Thank you for providing the font. We have been able to improve the feature, so expect tosee it with the next upcoming release.

[277967435 (Liu)]

Thank you very much, but after testing with version 3079, the merge contours feature still does not work. Please see the attachment.

Also, I’m not quite sure. Could you clarify the purpose of the 170° maximum angle?

Additionally, the rounded corner function may not be available for all fonts; for example, ‘×’ may not have rounded corners.

[ErwinDenissen]

I now understand, the Join Contours feature is available, but does not work. Better report individual issues in a new forum topic, but I will have it fixed with the next upcoming release.

The maximum angle is the flattest corner the feature will round. A corner’s opening angle is the angle between its two edges: 90° is a right angle and 180° is a straight line. Any point flatter than the set value is treated as effectively straight and is left untouched, so only real corners get rounded. At the default of 170°, anything within 10° of straight is skipped. Lower the value if you want to round only the sharper corners.

The feature is only applied to the glyphs you select, so you stay in full control of where it’s used. Just select the glyphs you want it applied to before running it. If a particular glyph isn’t rounded even when selected, it’s because its corners don’t match the current settings (for example they’re flatter than the maximum angle, or they’re not the corner type chosen under Corners).

[277967435 (Liu)]

Got it. Thank you very much, and look forward to the new version.

[ErwinDenissen]

Here is another update. Be aware it is not an official release, so things might change or break.

https://high-logic.com/tmp/fontcreator/FontCreatorSetup16.0.0.3080.exe