I welcome the option “save each track into a separate file” in the rendering window. I often use huge sample libraries. By selecting this option my pc is to slow to render all the tracks correctly at the same time.
It is possible to add an option with the function “save each track sequential into a separate file” ? 
Thanks.
Are you using VST plugins or only use internal samples / internal effects?
If you render using VST plugins you can use the “Real (VST compatability mode)” option which should at least render all tracks synchronized.
In this case all rendering is prioritized to wait until all VST buffers have been injected into the rendering stream before Renoise processes the next point of action.
The other render priority options (low and high) do not work out for various buffered plugins and cause overlaps or gaps in output.
Yes, i’m using a VST plugin (VSL Vienna Instruments). By rendering the whole song (saving all tracks to one wave file) it is no problem. But I need each single track for the further editing with adobe audition. The “Real (VST compatability mode)” option creates overlaps, gaps and partly empty wave files by selecting the option “save each track into a separate file”. So far I rendered each track separat by muting the other tracks. An “one click option” would be easier for me. 
If rendering to seperate tracks does not align all tracks together i would consider this a bug.
If you want to render each single track through muting you can also try the “Solo” button instead if you want t o have sort of a one-click option.