-there is an led tube. I think its cause the tubes ive been using need a starter and my fixture doesnt have one. another fixture has new fluorescent tubes, and it works just fine. can i get any help?

You're going to have to provide far more details.  I looked in your gallery and see you have Sears fixture with a starter, but here you're indicating the fixture does not have a starter.  Is this a different fixture, perhaps the 2xF40T12 with LED tubes?  What do you mean it "won't accept fluorescents unless there is an led tube"?  Are you simply saying that it works with a LED tubes, or that it's a two-lamp fixture and it works with one LED tube and one fluorescent?  Do you have pictures of the fixture and lamps?  Have you opened the fixture to see what kind of ballast it has?

What happens when fluorescent lamps are installed?  Does it not light at all, does one lamp light dim and the other not at all, or are both lamps dim?  Will they start up if you touch them?  If it's a rapid-start fixture, it'd be good to confirm it's grounded and that both lead wires are properly connected to each lamp holder.  Ensure the sockets are not damaged in a way that would prevent the lamp pins from making good contact.  LED tubes will often work with an ungrounded rapid-start fixture and with power to only one lamp pin at an end, but fluorescent lamps will have trouble if either of those issues are present.

this is a different fixture. it does not have a starter and has 2 normal sized T12 tubes. when i put another fluorescent bulb in, only the filament glows.  btw, it works with led tubes, or just one led tube and one fluorescent. i think it is a rapid start fixt.

It sounds like one of the two problems I described.  LED tubes have negligible resistance compared to an unlit fluorescent lamp, so the LED tubes alone or in combination with one fluorescent are easier to start than two fluorescent lamps in series.  You mentioned that the filaments glow.  Switch off all other light sources in the room and turn on the fixture in question.  Confirm that all four filaments illuminate.  If they don't, reverse or swap the lamps to determine whether the lamp or the socket is the issue. 

If the problem follows the lamp, it may have a broken cathode or the lead wires might not be crimped or soldered properly.  Try a different tube. 

If the filament at one particular socket never illuminates, inspect the socket for damage.  Make sure it's not cracked and ensure the contacts are not bent.  If it looks good, take off the reflector and with the power off, confirm the lead wires are snug.  Give them a light tug to make sure they are secure.  If nothing looks out of place, use a multimeter and measure the voltage across the two socket contacts.  It should be about 3.8-4V.  If you aren't getting a reading at the socket, test the lead wires themselves.  Note that if one of the two lamp holders on the yellow leads are missing heating voltage, it must be a socket or connection issue considering they are both tied to the same lead wires.  If it's the blue leads or red leads, it's possible the ballast is to blame.  Inspect the lead wires all the way back to the ballast looking for any breaks or bad splices.  Finally if everything seems fine but there's no heating voltage on a pair of leads, you'll need to replace the ballast in order to operate fluorescent lamps.  LED tubes do not require cathode heating, so there's no reason the ballast shouldn't continue to drive them indefinitely.

On the other hand if all four cathodes glow, then presumably heating voltage is present at each and the lamps are making good contact.  Try running a finger along the length of each tube while the light has power.  Most likely they'll pop on.  In this case, make sure the fixture is connected to grounded supply or cord set.  The ground wire should be attached to the frame of the fixture, and the reflector should be securely affixed to the channel.  If everything looks correct, use a multimeter and perhaps an outlet tester as well (if applicable) to make sure the fixture truly has continuity to ground.

If nothing works, the ballast might be bad and need to be changed to use fluorescent.  I'll also note that conventional rapid start magnetic ballasts can have trouble starting lamps in spaces without climate control, if it is cold or muggy.  Most of the time they should work, but low temperature and high humidity can increase tube resistance and interfere with the path to ground, making it tough for the ballast to initiate a discharge.

Found the fix! It literally says on the inside “USE RAPID START LAMPS ONLY” silly me

What were you using, some old lamps from the 1940s or 50s?  I didn't both to ask you were using RS lamps considering that they've nearly all been rapid start or preheat/rapid start for decades.

i was using lamps from around the 80s

Curious, unless they were labeled as preheat-only, I'd expect them to be rapid start lamps.  But, if you've got it working, great, hopefully it stays that way.  I'm in Michigan and F40T12 RS ballasts won't perform so well in my garage.  The lamps were very dim and flickery after startup, and on rare occasion they wouldn't start at all.  Now I'm using electronic, and while the the lamps will still be dim for a few minutes, they don't flicker and they always start.

Yeah I think F40 lamps have been rapid start compatible by default since sometime in the 60s. It was common on older fixtures to have that rapid start only label though. My louvered fixture, built in 1958 has that stamped on the side.

Rapid start was always pretty sensitive to bad socket contact, corroded lamp pins, and improperly seated lamps. I find even the electronic T12 rapid start ballasts sometimes have this problem too.

I have a couple of rapid start lights in my garage and they're not very well performing in the winter. The T8s are better but still need some time to warm up when it's cold. The best is the 8ft high output strip I have. That lights up immediately when fitted with full power lamps.