This is something will happen if you setup a part with two processes that has support. The default settings for support material configuration will set it up, so that you will have a gap of 2 layers in the middle of your support that is very-much unwanted.
The screenshot below is for a print of the Statue of Liberty, default supports and two processes.
Process 1- From 0 to 5 mm
Process 2- From 5 mm onwards
You can clearly see that there's missing support layers where the arrow points, where Process 1 ends, and Process 2 starts.
To fix this, we need to change settings in the Support Tab for each process.
In the Support tab settings, there's the option for Upper Vertical Separation Layers and Lower Vertical Separation Layers. In order to get rid of the Gap in the support in the picture above, you would need to change these settings.
Process 1- From 0 to 5 mm: Upper Vertical Separation Layers set to Zero
Process 2- From 5 mm onwards: Lower Vertical Separation Layers set to Zero
After those changes are made, the file will slice without any gap between the two processes.
If you're new to printing one part with different settings for different regions, the tutorial below is very helpful in explaining the process.
http://www.simplify3d.com/support/tutor ... f-a-model/