Why can't I see my machines?
The planner only shows what you've researched. A modded machine appears as soon as you research the technology that unlocks it.
To see everything, tick Show unresearched items in the planner's Settings (title bar button). It's also in Settings → Mod settings → Per player.
Why are some build options missing?
A build option with only one choice is hidden.
Options like recycler and pipe are always hidden since vanilla only adds one, if a mod adds alternatives they will be displayed.
Some options like chests or beacons are always hidden to make the UI more concise,
but you can enable Show all build options to see all options, including beaconed options.
Why do some machines get productivity modules?
Mixing a few productivity modules in with the quality modules often makes the loop cheaper per finished item, see: Quality Math. The planner calculates out the best ratios for the machines and modules you picked.
How do I change how many ingredients the loop requests?
Press Edit... beside Ingredient amounts in the planner. The Minutes field at the top sizes every amount at once: each ingredient is requested for that many minutes of crafting, two by default. Below it you get one field per ingredient of the recipe, and each tier's chest requests that many. If the amounts need more slots than the ingredient chest has, the planner warns you.
What is the active provider chest for?
Machines and recyclers sometimes roll an item above the quality you asked for. Nothing left in the loop can use it, so it would ride the belt forever and slowly fill it up. The planner taps it into an active provider chest instead, and your bots carry it away.
Why isn't my loop running?
Look at the constant combinator under the last machine. If it's switched off, a loop with a maximum is paused: switch it on. The planner places it switched off when Start paused is ticked in its Limits window, so a freshly built loop waits for its modules. The lamps below it show the state: blue while running, green when done or paused. A loop with no maximum has nothing to pause: switching its combinator off only removes the reserves, so keep it on.
If the combinator is on and the loop still sits idle, check its C row: 0 stops the loop rather than lifting the cap.
If you ticked Count the whole logistic network in the Limits window, every machine and recycler must stand inside roboport range. A machine outside any logistic network is switched off completely.
How do I change the limits after building?
Open the same combinator. The M rows are the minimum kept of each quality plus the inserter's hand size for every column of that quality, so a full hand never dips below your minimum: keep 20 with a 12-item hand and one column, and M reads 32. C is the maximum in the output chest. Edit the numbers, no new blueprint needed. To lift the maximum, type a big number: a C at 0 stops the loop. If you raise a minimum above what the stock chest requests while Trash unrequested items is on, raise the chest's request too, or that tier stops recycling.
With Count the whole logistic network ticked, the maximum is set on each machine, not on the combinator. To change it, set the new number in the planner and place the blueprint over the loop: the game updates the machines in place. The combinator's C row still pauses: set C to 0 or switch it off.
Why is my fluid recipe refused?
Only recipes with one fluid ingredient are supported. Two kinds can't be looped: recipes needing two different fluids (only ammonia rocket fuel in vanilla), and recipes that return a fluid alongside the item (like the quantum processor).