I have an error message after replacing my battery.

I have replaced my battery and everything was fine was getting 1.1 amps and an error message showed up. What should I do and is it fixable? Should I send my iPad to iPad rehab or is the data on this iPad lost forever because all I want is the data from the iPad. The iPad has been off for four years after it died on me and wouldn’t charge but after fixing the battery the message came up. any suggestions on where to send it also would help.

Thanks you Everyone.