when I checked out all my settlers it said this settler cannot be put on supply lines. its the sanctuary settlement.

one other thing though my food is in the red is only 1 should be at least 2 I don't know if this has any affect or not

I cant figure out why it wont let me assing a worker to supply line I have 5 settlers in sanctuary

I'm guessing those 5 settlers in Sanctuary are all the named ones that come with Preston? As far as I can tell, they can't be assigned to anything by you. Though it appears the game will auto assign them to farm if you have planted food. Plant some more food, make sure you have some water and defenses, and put up a recruitment beacon. Once you get that 6th settler, you can then assign that person to a supply line.

Oh! 5 settlers! That means you only have the original group and Codsworth. None of them will do supply routes.

Once you've put up your beacon others will show up and you can assign them to it.

I found that one out the hard way.

do I have to have settlers in both towns? I want to supply line to rocket or whatever gas station. I now have 6settlers and still I do not get the option to assign to supply line I made a bell and rang it to get them all together and cant figure out why I cant make a supply line. what if I click send to? is only way I can see a list of cities

build a radio beacon to attract more settlements don't seem to grow w/o one

yea i did i built a bunch of stuff to accomadate somewhere round 10-12 settlerts but right now i have 6 and cant seem to get the unnamed settler to assign to supply line suggestions ?

As others have mentioned, or maybe it was you, it could be your low food, so how bout we eliminate the maybes.

0. Scrap all TVs as there seems to be some bugginess fixed by just having no TVs.

1. Make like 5 more beds than the number of people you have in your settlement now.

2. Get your food up to like 15 or so, based on the number of settlers you said you had and should be getting soon. (Go to a farm and pick some non-wild stuff and use that to plant, as wild versions do not seem to like to be planted. The two different types in the settlement UI are just the looks of the plant, in the case of Razorgrain the size is noticeable.) Settlers can pick 6 plants each I think it is, so you could plant up to 36 for the intial group that heads to sanctuary, but I have found that at least early on, getting Preston and Sturges and even Mama Murphy to do something can be frustrating.

3. Get your water up to maybe even double your food number. BTW, excess food and water is stored in your workbench and you can sell it, so be smart and actually make way more purified water than you need and have extra coming in all the time to sell...and heal.

Sanctuary has the benefit of the Settlement area including water, so without a ton of perks or a ton of rare materials you can build a large water purifer, or two that can run off the generator that produces 5 electricity.

4. Get your defense up. It should always be higher than your Food and water combined to keep the attacks on your settlement low. Guard posts must be manned to get the defense bonus, so focus on the lowest level turrets to get more defense points for less overall resouces like gears and oil and such, used.

5. Build a generator and Settlement beacon to attract more settlers, as you will not get any more people showing up without setting that up.

6. Have the Base Charisma of 6 and your Local Leader Perk at Rank 1 so you can establish supply lines.Temporary Charisma increases can increase the maximum number of settlers, but once it goes back it can be welcome to buggy if you assigned settlers that have decided they are now leaving, so don't switch around gear while going in and out of the Settlement UI, and then have your character sleep on it to firm up what you just added or changed.

7. Select a settler that is called a Settler, not a named one like Sturges or Mama Murphy

8. Sleep on it to reset things before trying to quit and restart the game.

Once you've gone that far and still have a problem with assigning a single settler to be the supply line between two settlements, then we can start really thinking on this.

is this a must have to get supply lines

6. Have the Base Charisma of 6 and your Local Leader Perk at Rank 1 so you can establish supply lines.Temporary Charisma increases can increase the maximum number of settlers, but once it goes back it can be welcome to buggy if you assigned settlers that have decided they are now leaving, so don't switch around gear while going in and out of the Settlement UI, and then have your character sleep on it to firm up what you just added or changed.

Without the local leader perk, you can't have supply lines.