I changed the exposure compensation to manually bracket photos, changed the D Lighting.Regardless of mode I am in the display indicates the image is to dark and the shutter will not release, where do I go from here?

We need far more information - lens in use, shutter speed and aperture settings, white balance setting, ISO setting, exposure compensation, lighting conditions, subject matter etc. All of these have a bearing on exposure. From your description, it sounds as if your images are seriously under exposed. Have you looked in the trouble-shooting section of the camera manual ?

just change the backlight and contrast settings in camera .....regarding flash try taking photos with new batteries ...

According to the manual for your camera, if none of the indicators are on when the shutter release is half pressed, the batteries are exhausted. If the 3 lights are on at the same time, exposure is correct, if only the plus or minus is displayed under/overexposure is present.

Be sure to check your film speed settings, as even if your camera is telling you your exposure is correct, if the film speed isn't correctly set, your images will not be properly exposed if the camera is not set for the film actually loaded in it. Otherwise, check your batteries.

Also, keep in mind some lighting conditions can trick your meter and may need to be compensated for. If your camera has an exposure compensation dial, which yours should, check to be sure it is set to "0" as this could also cause your exposure issues if it's been moved previously and never reset.

Here's a link to your camera's manual, unfortunately it's not very visual so it's hard to get a very good idea of exactly what features your camera may or may not have.

http://www.cameramanuals.org/pdf_files/vivitar_v3800n.pdf

Yes, there is a setting called exposure compensation, which you may have altered.
Try switching the camera back to A (Auto) mode, and see if that fixes it.
In the manual setting modes, exposure compensation will look like this:
http://images.digitalcamerainfo.com/images/upload/Image/new/Photokina08/Canon/sd880is/photos/Canon-sd880is-menu-functionset-375.jpg
Make sure that you haven't set the exposure compensation to +2, for example. It should usually be set on 0.

l For manual copy density adjustment, press the AUTO/
MANUAL/PHOTO ( / / ) key to select
MANUAL ( ) and adjust with the LIGHT ( ) and
DARK ( ) keys as desired.
l For photographs, select PHOTO ( ) and then adjust with the
LIGHT ( ) and DARK ( ) keys as desired.
l There are 9 exposure steps indicated by 5 indicator lights. (The
indicators light up one or two at a time.)
Successive pushes of the LIGHT ( ) key will change the
indicator lights in the order (3) / (3•2) /(2) / (2•1) / (1).
Successive pushes of the DARK ( ) key will change the
indicator lights in the order (3) / (3•4) / (4) / (4•5)/ (5)
The automatic exposure level can be adjusted to suit your copying
needs.
1 Press the AUTO/MANUAL/PHOTO ( / / ) key
to select the PHOTO ( ) mode.
2 Press and hold the AUTO/MANUAL/PHOTO ( / /
) key for approximately 5 seconds.
l The PHOTO ( ) indicator will go out and the AUTO indicator
will begin to blink.
l One or two exposure indicators corresponding to the automatic
exposure level which has been selected will light up. The factory
default setting is level “3”.
3 Press the LIGHT ( ) or DARK ( ) key to lighten
or darken the automatic exposure level as desired.
4 Press the AUTO/MANUAL/PHOTO ( / / ) key.
l The AUTO indicator will stop blinking and will light up steadily.
l This automatic exposure level will remain in effect until you
change it again by this procedure.
Automatic exposure adjustment
AUTO

OM-20 was basically a upgraded OM-10 with the manual adapter built in and a number of other refinements.

The viewfinder has LED's to show the shutter speed recommended by the camera's lightmeter for the ISO and aperture selected. It also has an exposure compensation indicator (the +/- symbol) and an indicator for flash ready which doubles up as a post-exposure flash confirmation. There is also the indicator lamp to show manual mode has been selected. OM-10 lacks the manual mode lamp and the +/- indicator.

Like the OM-10, the OM-20 is primarily an aperture priority automatic camera. In this mode you set the ISO film speed, choose which aperture you wish to use (with the ability to use the lens depth of field preview button) and then the camera selects the correct shutter speed. The +/- exposure compensation control allows the user to tell the camera to modify the recommended shutter speed by up to two stops either way.

In manual mode, there is no manual metering. The light meter behaves exactly as it does in aperture priority mode and the viewfinder shows the recommended shutter speed and not the manually selected one. Correct metering is therefore a case of adjusting the aperture first, and then choosing the correct shutter speed indicated in the viewfinder. If the user then decides to select a different shutter speed, then the aperture ring must be adjusted to maintain the correct exposure. For example the aperture is set to f8 and the camera recommends 1/60th of a second. The user decides that a faster shutter speed is required and chooses 1/250th, but the viewfinder remains showing 1/60th. In order to keep the same exposure value the user must open the aperture by two full stops to f4. The camera's light meter will detect the new aperture setting and providing the light on the object is unchanged the viewfinder shutter speed display should now show 1/250th as well to confirm the correct adjustment. Alternatively, the user can choose the shutter speed first by looking at what has been set on the control ring (or by turning the ring to the end of its travel and then counting the clicks from there as all experienced OM users do) and then turning the aperture ring until the shutter speed shown in the viewfinder matches what's been manually set.

It all sounds clumsy and complex but is done far more quickly than I've taken to type this and becomes second nature.

Aperture priority metering is selected on the camera by choosing AUTO on the mode selecter. In this mode the shutter speed ring has no effect and the viewfinder always displays the automatically selected shutter speed.

You are exposure compensation in manual mode. If you want the shots lighter, either open up the aperture or slow the shutter. The exposure compensation feature is to override the automatic settings determined by the camera in the auto-exposure modes.

It sounds like the camera exposure system is out of whack and may need to be serviced. You may want to ensure that exposure compensation is set to 0. Check one of your overexposed images with the display in the 'Detailed Display' mode (two lines of information at the bottom of the LCD). If the second item on the top line is not ±0, the exposure compensation is not at its default value. To set, put the camera in M(anual) shooting mode. Press the Exposure/White Balance button until you see a scale along the bottom of the LCD from -2 to +2. Use the left or right button to set it at 0. If the value is already at 0, you will probably need service.

Probably needs a good cleaning. The mirrors get dusty. I would suggest you call a tech. to do it. As you can nock something out of wack.

Use the bracket exposure method. or read the apeture off then up a stop.