Before the software can communicate with your printer, it must be placed into a special diagnostic state called "Service Mode." The method can vary, but for the Canon MP250 series, the most commonly recommended steps are:
This is the main operation you will likely need to perform. service tool v1074 canon mp250 download link
To restore your printer to full functionality without paying for expensive professional repairs, you need a specialized software utility called Service Tool V1074. This comprehensive article provides everything you need to know about finding a safe download link, putting your Canon MP250 into Service Mode, and safely resetting the internal counters. What is Canon Service Tool V1074? Before the software can communicate with your printer,
Your computer will not recognize the printer in the software unless it is in first: Turn off the printer but keep it plugged in. Press and hold the Stop/Reset button (triangle icon). While holding Stop/Reset, press and hold the Power button. What is Canon Service Tool V1074
If you provide more details, I can tell you if a newer version of the tool is required, or if a manual reset is possible.