How do I have one quest begin after the previous has been completed in a questline chain?

[gookey]

I am creating a questline for my custom follower which has more than 1 quest. I get my first quest completed, but the secon one won't start.  I tried almost all the troubleshooting methods and it still won't work.

[xkkmEl]

Use quest fragment scripts.

In the CK, open the quest and go to the quest stages tab.  Add a final stage.  In that final stage's script fragment box, add a line to start the next quest (and create+fill the corresponding property).

[scorrp10]

In quest stages, if on a stage, you check either 'Complete Quest' or 'Fail Quest' box, you can choose which quest will start next.    That is one option.

Another option, in any script that gets run in the course of your quest - dialogue fragment, quest stage fragment, script on an alias, etc.  you can declare a quest property, fill it with your next quest, and in a proper place, call Start() method on that property.

You can also start quests via Story Manager events, when some event  occurs (i.e player talk to actor or increase level), you can put completion of prior quest as a condition on the SM node.