Yes, you have too many sounds. You cannot export an animation with more than about 64 sounds currently. If you change the visibility of your sound layers to hidden, you should be able to at least export your animation to a video without audio. You may be able to export the the audio exporting four times, each with only one of the sound layer active, but this will only work if each of your layers has less than the maximum number of sounds.
In the future, we recommend you break your animations up into small segments (ex. per shot) and combine them together in the end with a video editor. This reduces the resources required to work on a project, reduces the risk of loosing lots of work if a project file becomes corrupted, and helps avoid issues like this.