If BuildFlow prevents you from printing a model or it doesn't print properly, there may be an issue with how the model was created. You may see a message like the ones below:
These are the things to check for:
1. A lot of these errors are caused by models that aren't watertight, have intersecting faces or are invalidly defined. Usually, you are able to fix these bad models by 'repairing' them. You can easily do this by using 3D Builder or Netfabb repairer. More info can be found here.
2. Most other errors will be caused by overly complex models. Complex models may not slice properly or print as expected. This may not be apparent at first glance, but it is any easy fix for most models. Details in a model can either be from small components (or small model as a whole) or having a complex outer surface with lots of 'faces'. More information on reducing the face count of your models can be found here: Reducing file size - Face count
You may be able to scale up your model in CAD software to increase the size of these small details, especially if it is something you designed yourself.
Once any changes have been made and saved to your model, you will have to upload the new version to your BuildFlow account. It is also best practice to delete the old file from your account to avoid confusion in the future.