The brother dcp-l2540dw offline error is popping up constantly falling for a variety of causes, including:
• Blockage of the ink toner
• The printer isn't set to be the default.
• A network connection error has occurred between your computer and printer.
• Due to a print job that is stalled in the queue
• Printer drivers that are corrupted or out of date.
• If the printer's 'use offline mode' option is chosen, the offline error may appear.
• The printer settings are incorrect.