Toshiba dvd recorder D-R17DTKB error E4 54037380. What is wrong? New disc inserted

You are either using the wrong type of disc. They come in "+" or "-" types. Your recorder should tell you which it is. Or you are not formatting the discs before use. Or you have bought some counterfeit discs which will never work!

If its an older recorder it could be the usual problem of a greasy center-disc =
95% OF THE TIMES I could fix a problem like this was by cleaning with rubbing alcohol the rubber ring on the little rotating disc in the center of the drive mechanism. !!!! Because users always stick their index finger into the hole of all the CD'S for inserting a disc into the tray that a tiny amount of grease gets deposited onto the little rotation disc which touches the center of any inserted disc at about half an inch from its center hole. (underneath) When its greasy the discs slide and the inserted discs speed stays uneven and slow.
You must open the drivebox ( after unplugging the power-cable) to see and clean it.
Be careful to not look at it with power "on" because the laser will make you go blind (danger!!!!!!!
I heavily use a Toshiba DVD recorder since 12 years and it is my most reliable and most versatile recorder, while my brand new Sony recorder lasted only 2 years - Others as well had problems with finalizing etc. but in general the cleaning of the little center-disc that pushes from underneath against an inserted DVD to make it spin helps the most.

I have a Toshiba HDD&DVD vcr RD-XV48DTKB will not accept disc or play any disc have tried several makes even new ones it just loads then says error cannot play eject will not play or record HELP

Multiple problems with the DVD recorder one of them could be the lasers not reading correctly its software is messed up or there something wrong with this but to me it sounds more like the DVD recorder has a problem I've experienced this problem before not with this particular type of DVD recorder I fix the problem by unplugging the DVD player for about 20 seconds to a minute to give it a good reset.
Quick tip: most high Tech Device problems or unknown errors can be fixed by simple restart or reset hope this helps

You can get this if you´re using RAM-discs previously recorded/formatted on a different recorder. Clean the disc REALLY WELL and try inserting several times, it may pass.

≥The disc is scratched. Use another disc.
≥The disc is dirty.
≥You inserted an incompatible disc

I have same TOSHIBA D-VR4XSU VCR/DVD RECORDER. According to the
manual, you (COULD) can use for recording: DVD-RAM, DVD-RW and DVD-R (see page 50). WRONG!!! I bought all 3 types of discs, but after few
weeks I got same experience you got now. Just type DVD-R works. The other
types were - wasted money and a lot of time trying to finalize the disc. I had to
throw all into the garbage. Try DVD-R and you should?? be O.K.

Sounds like the laser has gone or the try is not fully loading the disc.

Check formatted disc see if it's +R,-R and see if Toshiba will play homemade disk or just disc recorded in different format.

Check to see if you are using 16x media.  If you are you need to get a firmware upgrade from Toshiba.  Contact their support number listed inside of the manual.  They will ship you a dvd to insert into the unit.