Clicking the About button causes an error

[soaressgabriel]

Describe the bug
Clicking the About button causes an error and the plugin information window is not displayed.

To Reproduce
Steps to reproduce the behavior:

1. Open RUBEM Hydrological;
2. Click on About button;
3. See error happening.

Expected behavior
Clicking the About button brings up a new window with information about the plugin.

Screenshots

errorlog.txt

Desktop (please complete the following information):

• OS: Windows 11 Home 21H2 (comp. ver. 22000.384)
• QGIS: 3.22.a-Białowieża (663dcf8fb9)
• RUBEM Hydrological: 1.11.0

Additional context
Earlier versions, like 1.3.2, work without problems.