I have been trying for a week to get my lightmap bakes to look halfway decent. I havent baked lightmaps since Unity 3 and I thought I wouldn’t have to deal with the same problems (i.e. long bake times, poor res maps, etc). I am still getting very strange results. If I crank up the settings and resolution I can’t get anything to finish baking (It is like my computer just stops trying after about 1 hour). But with the settings low enough to finish the baking process I get horrible looking blotches. Here’s a screen cap. If anyone has any suggestions please share!
Try turning off compression. Also, are you sure you have proper lightmap UVs?
I have done it with both compression on and off and still get those splotchy lines. 
I have generate lightmap UVs on also. I would make my own but the project has literally hundreds of models that I did not originally create and going back in and creating them would be too time consuming. I notice that it only happens on areas affected by lights with shadows turned on. Is there something I should do with shadow settings maybe?
show us your light settings, it may be the shadow bias.
It is a directional light casting soft shadows with a baked angle of 1.7 and and intensity of .62 and a bounce intensity of .08
An ray count of only 2 is very very little, try turning final gather off instead.
It never finishes baking if i turn off final gather (and i have tried many times). I tried with many rays, with no rays, with few rays. Pretty much I have done bakes with all the obvious settings in various different amounts. I was just hoping some who had this problem before might know specifically why this happens. I already have done the guessing which settings are what troubleshoot. Thank you for trying though
Hey @ChayChay , we are together on the bake blotching boat 
Now about your issue with “never finishing baking”, how long did you wait for it? We are doing some bakes that take several hours (24 with our old bake machine, 8 with the new one), so unless you have a BSOD or Unity is spending 0% processor and RAM usage is stalled on a fixed value, he is alive and baking 
For a fast-track bake, try the following:
-Reduce atlas res to 32 (shadows will suck like heck)
-Break any geo prefabs you have on the scene. Yup, just break all the prefab links.
-You can punch up textel resolution to 320
-enable Generate lightmap UVs on mesh import
This should be a very fast bake. I guess that depending on geo, add 30% more time if final gather is on (with around 1000 rays minimum).
For my experience, you only increase atlas size you have light intensity and a ballpark idea of the shadows. 512 resolution should be enough in most cases. If it really turns out nice and your scene is big enough, then you cranck it up to 1024 or 2000’s range.
Give it a try and let me know if this helped your speed