Are you new to AE? If the last part of the comp won't show up when you preview then you could be running out of system resources. Previews are rendered and it's not often that a 10 minute comp will playback all the way. CC 2017 improves this, but the quality and duration of the playback depends on your system and the comp settings.
Your screenshot doesn't show us much about your composition. You should select all layers then press the U key twice to reveal all modified properties of all layers. Then scroll down the timeline and down the list of layers until you can see what has been modified on the layers that are giving you problems. If there's something wrong with the workflow or with an effect you have added to the comp you should be able to spot it. If you cannot then please Print Screen and paste a full screenshot of your project to this forum.
I'm also not sure about your composition settings. Unless you are an expert at video formats and frame rates your composition settings should never say Custom. You should be using the presets. No custom frame sizes or frame rates until you know exactly what you are doing and make sure that the preset that you pick uses square pixels. Some of the legacy and camera format presets use non square pixels and these will cause you a bunch of trouble for most video production.
Sorry for this issue. Did you ever find a solution? Please let us know if our expert's advice helped you or if you still need help.