iFox iControlLib v2 user defined icon

Hello!

The manual states that: "User-defined icons start at value of 10000. For example, if the symbolOn is set to := 10000, the application at value = TRUE displays the icon given by the image named 10000.png, which must be stored in the WWW / iFOX / directory on the SD card in the PLC. If the 10000.png file is saved in the Mosaic project to the SendRoot folder, the iFOX file is automatically saved to the SD card in the PLC when the translated program is first sent to the PLC."

When try to set the user icon according to this manual no icon is displayed in iFoxtrot app. I checked and the png file was copied to the WWW/iFOX folder, but is still not displayed.

The png file in question is 24x24 pixels. What could be wrong? Or need to be checked?