[BUG]: Application fails to start when printer is off (hangs on "Waiting for printer connection" and exits silently) #2230

Brief description of the issue

After upgrading from 5.0.4 to 5.1.0, RSS Guard fails to start if my printer is turned off. A dialog appears saying "Waiting for printer connection..." and the application then exits silently. If the printer is turned on, the application starts normally. This issue did not occur in version 5.0.4.

How to reproduce the bug?

1. Turn OFF printer
2. Launch RSS Guard 5.1.0 (portable build)
3. Wait for the "Waiting for printer connection..." dialog
4. Click "Cancel" or wait

What was the expected result?

The application should start normally regardless of printer availability.

What actually happened?

The application shows a dialog titled "Waiting for printer connection..." with the message "Please wait for printer connection or cancel connection." After canceling or waiting, the application closes silently and does not start.

Debug log

time=" 0.095" type="debug" -> core: Starting to load active localization. Desired localization is 'en_US'.
time=" 0.096" type="debug" -> core: Application localization 'en_US' loaded successfully, specifically sublocalization 'en_US' was loaded.
time=" 0.096" type="warning" -> core: Qt localization 'en_US' WAS NOT loaded successfully.
time=" 0.098" type="debug" -> database: Executed query:
SELECT inf_value FROM Information WHERE inf_key = 'schema_version'
time=" 0.098" type="debug" -> database: Executed query:
PRAGMA foreign_keys=ON;
time=" 0.098" type="debug" -> database: Executed query:
PRAGMA encoding = 'UTF-8';
time=" 0.098" type="debug" -> database: Executed query:
PRAGMA page_size = 32768;
time=" 0.098" type="debug" -> database: Executed query:
PRAGMA cache_size = 32768;
time=" 0.098" type="debug" -> database: Executed query:
PRAGMA mmap_size = 100000000;
time=" 0.098" type="debug" -> database: Executed query:
PRAGMA synchronous = OFF;
time=" 0.098" type="debug" -> database: Executed query:
PRAGMA temp_store = MEMORY;
time=" 0.098" type="debug" -> database: Executed query:
PRAGMA journal_mode = WAL;
time=" 0.098" type="debug" -> database: Executed query:
PRAGMA busy_timeout = 5000;
time=" 0.099" type="debug" -> database: Executed query:
SELECT inf_value FROM Information WHERE inf_key = 'schema_version'
time=" 0.099" type="debug" -> database: Executed query:
PRAGMA optimize;
time=" 0.100" type="debug" -> gui: Available icon theme paths: QList(:/graphics, S:\Apps\RSSGuardText\data5\icons, S:/Apps/RSSGuardText\icons, :/icons)
time=" 0.100" type="debug" -> gui: Installed icon themes are: '', 'Breeze', 'Breeze Dark'
time=" 0.100" type="debug" -> gui: Loading icon theme 'Breeze'.
time=" 0.100" type="debug" -> gui: Found path of base skin: ':\skins\minimal-base'.
time=" 0.100" type="debug" -> gui: Base file ':\skins\minimal-base\html_wrapper.html' exists, using it for the skin.
time=" 0.100" type="debug" -> gui: Local file ':\skins\minimal-light\html_style.css' exists, using it for the skin.
time=" 0.101" type="warning" -> QPalette::brush: Unknown ColorGroup: 5
time=" 0.101" type="warning" -> QPalette::brush: Unknown ColorGroup: 5
time=" 0.101" type="debug" -> gui: Base file ':\skins\minimal-base\html_enclosure_image.html' exists, using it for the skin.
time=" 0.101" type="debug" -> gui: Base file ':\skins\minimal-base\html_single_message.html' exists, using it for the skin.
time=" 0.101" type="debug" -> gui: Base file ':\skins\minimal-base\html_enclosure_every.html' exists, using it for the skin.
time=" 0.101" type="debug" -> gui: Local file ':\skins\minimal-light\qt_style.qss' exists, using it for the skin.
time=" 0.101" type="debug" -> gui: Base file ':\skins\minimal-base\qt_style_forced.qss' exists, using it for the skin.
time=" 0.101" type="debug" -> gui: OS defines color scheme: 'Qt::ColorScheme::Light'.
time=" 0.101" type="debug" -> gui: Setting style: 'Fusion'.
time=" 0.101" type="debug" -> gui: Activating alternative palette.
time=" 0.101" type="debug" -> gui: Skin 'minimal-light' loaded.
time=" 0.101" type="debug" -> network: Disabling application-wide proxy completely.
time=" 0.105" type="debug" -> core: Platform: 'windows'.
time=" 0.105" type="debug" -> database: DB read job (with return) in thread 40276.
time=" 0.105" type="debug" -> database: Executed query:
PRAGMA foreign_keys=ON;
time=" 0.105" type="debug" -> database: Executed query:
PRAGMA encoding = 'UTF-8';
time=" 0.105" type="debug" -> database: Executed query:
PRAGMA page_size = 32768;
time=" 0.105" type="debug" -> database: Executed query:
PRAGMA cache_size = 32768;
time=" 0.105" type="debug" -> database: Executed query:
PRAGMA mmap_size = 100000000;
time=" 0.105" type="debug" -> database: Executed query:
PRAGMA synchronous = OFF;
time=" 0.105" type="debug" -> database: Executed query:
PRAGMA temp_store = MEMORY;
time=" 0.105" type="debug" -> database: Executed query:
PRAGMA journal_mode = WAL;
time=" 0.105" type="debug" -> database: Executed query:
PRAGMA busy_timeout = 5000;
time=" 0.105" type="debug" -> database: Executed query:
SELECT sqlite_version();
time=" 0.105" type="debug" -> core: DB version: '3.51.1'.
time=" 0.105" type="debug" -> core: OpenSSL backends: 'QList(cert-only, openssl, schannel)'.
time=" 0.105" type="debug" -> core: OpenSSL version: 'OpenSSL 3.0.16 11 Feb 2025'.
time=" 0.105" type="debug" -> core: OpenSSL supported: 'true'.
time=" 0.105" type="debug" -> core: Global thread pool has 16 threads.
time=" 0.105" type="debug" -> core: Main thread ID: '40276'.
time=" 0.105" type="debug" -> core: Setting locale for LC_NUMERIC to C as libmpv requires it.
time=" 0.105" type="debug" -> core: Instantiated class 'Application'.
time=" 0.111" type="debug" -> message-model: Repopulate started.
time=" 0.111" type="debug" -> database: DB read job in thread 40736.
time=" 0.111" type="debug" -> database: Executed query:
PRAGMA foreign_keys=ON;
time=" 0.111" type="debug" -> database: Executed query:
PRAGMA encoding = 'UTF-8';
time=" 0.111" type="debug" -> database: Executed query:
PRAGMA page_size = 32768;
time=" 0.112" type="debug" -> database: Executed query:
PRAGMA cache_size = 32768;
time=" 0.112" type="debug" -> database: Executed query:
PRAGMA mmap_size = 100000000;
time=" 0.112" type="debug" -> database: Executed query:
PRAGMA synchronous = OFF;
time=" 0.112" type="debug" -> database: Executed query:
PRAGMA temp_store = MEMORY;
time=" 0.112" type="debug" -> database: Executed query:
PRAGMA journal_mode = WAL;
time=" 0.112" type="debug" -> database: Executed query:
PRAGMA busy_timeout = 5000;
time=" 0.112" type="debug" -> database: Executed query:
SELECT Messages.id, Messages.is_read, Messages.is_important, Messages.is_deleted, Messages.is_pdeleted, Messages.feed, Messages.title, Messages.url, Messages.author, Messages.date_created, Messages.contents, Messages.enclosures, Messages.score, Messages.account_id, Messages.custom_id, Messages.custom_data, (SELECT GROUP_CONCAT(Labels.custom_id) FROM LabelsInMessages lim JOIN Labels ON lim.label = Labels.id WHERE lim.message = Messages.id) AS msg_labels FROM Messages WHERE 0 > 1 ;
time=" 0.112" type="debug" -> message-model: Repopulated model!
time=" 0.112" type="debug" -> core: Auto-download timer started with interval 10000 ms.
time=" 0.112" type="debug" -> core: Creating FeedDownloader singleton.
time=" 0.114" type="debug" -> gui: Creating main application form in thread: '40276'.
time=" 0.118" type="debug" -> gui: Current row changed - proxy 'QModelIndex(-1,-1,0x0,QObject(0x0))' and source 'QModelIndex(-1,-1,0x0,QObject(0x0))'.
time=" 0.118" type="debug" -> message-model: Setting additional ID of article to be excluded from filtering or reselected after model reset to '0'.
time=" 0.118" type="debug" -> gui: Article list header geometries changed.

Operating system and version

• OS: Windows 10
• RSS Guard version: 5.1.0 (portable build)