Bookworm crashes when a certain TTS engine tries to read specific strings in a document

[k-kolev1985]

Describe the Problem

In Bookworm v0.4, if the bulgarian SAPI5 TTS engine/voice "Irina" tries to read some specific strings in a document, Bookworm will crash. I haven't manage to determine yet what are those specific strings. The document with which it happens is not a specific one - it just has to contain those specific strings. The problem does not occur with the same string in the same book with the same voice used in the stable release of Bookworm. The crash does not occur with the only other bulgarian TTS engine/voice that appears in Bookworm 0.4 portable - the OneCore bulgarian voice "Ivan". I've reproduced the problem/crash with debug mode enabled in Bookworm and will attach here the logs created by Bookworm.

To Reproduce

1. Install the bulgarian SAPI5 voice "Irina".
2. Launch Bookworm 0.4. I use the portable version but I don't know if it matters.
3. Configure Bookworm to use the bulgarian voice "Irina". Set its speed to 75% and its volume to 100%.
4. Open a document in bulgarian, that contains a string with the problematic for "Irina" syntax.
5. Find the problematic string and move the cursor to the beginning of the line that contains it.
6. Press F5 to read that line using the voice "Irina". "Irina" will start reading the line and Bookworm will crash.

Expected behavior

"Irina" should read the string without causing Bookworm to crash.

The File You've Opened

The file type seams not to matter, but my e-books are usually in EPUB format. The specific string seams to matter. My books are in bulgarian/cyrillic.

Desktop (please complete the following information):

• OS: Windows 10 Pro version 21H1 (build 19043.985), 64-bit, in Bulgarian with all locale settings set to "Bulgarian".
• Bookworm version: 0.4b1.

Additional context

I can provide you privately with a book with such problematic strings and a demo of the voice "Irina", if needs be.

Bookworm_Logs_2021-06-07.zip