Hello Peter, Debut has a limit of 10 hours continues recording, after the time limit is reached the program offers the option to create a new recording and continue or to stop recording. You may want to check those settings under Debut > Options > Record > Limits.
Also, keep in mind that recording continuously may create a file to large for your computer to handle. Also, video recording maybe an intense process for your computer depending on the format you are using to record. You may want to try using different formats and encoders to find what your computer can handle better. Sadly, there is no specific format or settings we can recommend as that will depend on the computer's specifications.