Contact lense I probably have some dirt in the lens. How do I clean it?

No, you shouldn't clean your CD/DVD player lenses with contact lens solution. It is inappropriate to put contact lens cleaning on the CD/DVD player's lens because it is made for the delicate surface of the eye. A CD/DVD player's lens can become harmed and malfunction if contact lens cleaning is applied to it.
Use a soft, lint-free cloth and a cleaning solution made especially for CD DVD players to clean the lens if necessary.

Cleaning the lenses of night vision devices requires some care and attention to avoid damaging the delicate components of the device. Here are some steps to clean the lenses of a night vision device:

1. Use a blower brush: Use a blower brush or a can of compressed air to blow away any loose dust or debris on the surface of the lens. This will prevent scratching the lens when you wipe it later.
2. Use a microfiber cloth: Use a microfiber cloth specifically designed for cleaning lenses to gently wipe the lens in a circular motion, starting from the center and working outward. Be careful not to apply too much pressure, as this can damage the lens coating.
3. Use lens cleaning solution: If the lens is still dirty, you can use a small amount of lens cleaning solution. Apply the solution to the microfiber cloth, not directly on the lens. Wipe the lens gently, and then use a dry part of the cloth to remove any excess moisture.
4. Repeat if necessary: If there are still spots or dirt on the lens, repeat the cleaning process until the lens is clean.

To remove dark lines on the lens of a night vision device, you can try the following steps:

1. Use lens cleaning solution: If the dark lines are caused by dirt or debris, you can try using a small amount of lens cleaning solution and follow the cleaning steps mentioned above.
2. Use a lens pen: If the dark lines are caused by smudges or fingerprints, you can try using a lens pen specifically designed for cleaning lenses. These pens have a soft brush on one end for removing loose debris and a microfiber tip on the other end for wiping away smudges.
3. Contact the manufacturer: If the dark lines persist or if they are caused by a defect in the lens, you may need to contact the manufacturer for assistance or repair.

It's important to note that cleaning night vision lenses can be tricky and it's best to follow the manufacturer's instructions or consult a professional if you're not sure about how to clean them. Also, avoid using harsh chemicals or abrasive materials that can damage the lenses.

The Canon Err 01 is called Lens communication.
The lens has lost communication with the camera, or vice versa. This can be caused by dirt or grease on the gold coated contacts. On the lens or in the camera.
Try cleaning the contacts, with a dry cloth or cotton swabs. Don't use any sharp tools or force. To pinpoint where the error is, you could try to place another lens. If the error disappears most likely the first lens caused the problem. If the error stays, you should suspect the camera.
If you only have the problem with one lens, and the contacts are clean, contact a certified Canon repair centre.

Canon can have tight tolerances for their lenses and camera bodies. Some aftermarket lenses don't mate well. If the problem occurs with other lenses as well, try cleaning the contacts on the lens and camera with a clean, soft cloth or rub them VERY LIGHTLY with a new, clean pencil eraser, taking care no particles drop into the camera or lens. If this doesn't correct the issue you probably have a damaged contact or lose contact in the camera or lens.

1. Carefully clean your binoculars by firstly removing any dirt or dust from the main body and straps using a soft microfibre cloth. Avoid the lenses at this point using any form of cloth on the lenses before removing all dirt and dust particles first could destroy them.

1. Gently remove all traces of grit, dirt or dust particles from the lenses using a soft lens brush or canned air specifically designed for the purpose.

1. Waterproof binoculars can be rinsed gently under a tap but be sure to use on lightly running water, avoid high pressure water as it could damage your binoculars.

1. Gently remove any remaining marks using lens cleaning tools such as a lens pen or lens cleaning fluid and lens tissue. Do not be tempted to use kitchen towel or anything else lying around that is slightly rough and may scratch the surface of the lens, only use a lens pen, lens tissue or a lens cloth. Gently wipe the lens using a circular motion working from the centre of the lens to the outer edge. NEVER apply lens cleaning fluid directly onto the glass (always apply to the cloth) and always ensure that the lens cleaning fluid you are using is recommended for the type of lens coatings that have been applied to your binoculars (Do not use general household glass cleaning products or products designed to clean computer screens or glasses. Such products could destroy the lens coatings of your binoculars if used).

The lens most probably has dirty contact between the lens and camera body. It only worked with the "default" lens because you disturbed the dirt removing the 17-85 lens.

Here is what I'm suggesting, seeing you said the problem was solved by changing out the lens.

Clean the contact both on the lens and camera body with a pencil eraser, hold the camera body so the lens cavity is pointed downward and lightly polish the contacts don't use a puffer to clean the area you will just blow dirt into the camera.

Do the same with the lens contacts and you will be good to go

Rob, Error 99 is Canon's catch all error code, yes my first impression would also have been to clean the contacts but something else that is happening is the camera firmware may need to be updated to handle that particular lens. Camera updates are free on the Canon site and actually can solve a lot of hidden processing problems.

That lens isn't really suitable for your 450d as it's an APS-C sensor size with a 1.6 crop focal factor which will give you more like a 24mm focal length.

You may also want to format the memory card and clean your battery terminals both the battery and the contacts in the battery compartment.

Best little cleaning item for cleaning contacts is a pencil eraser (new) lens contacts or battery something about the soft rubber cleaning off the most suborn dirt and electrolysis.

Don't use a "used" eraser obviously it will transfer the dirt to the contacts over removing what you want.

Hope these techniques work they have for me

This usually means your camera is not communicating with the lens properly. Inside the body of the camera - directly above the opening for the lens mount - are 7 square / rectangular pads. These pads are the electrical contact points, that when mated to the corresponding pins of an automatic Nikon (or compatible) lens, provides the signals to set / confirm f-stop, focus, etc.

Since this is occurring on several lenses, unless you're failing to install the lenses fully into the body, the issue probably lies with the camera body itself. There may be an issue with dust, dirt or oxidation on these contacts - or a problem inside the camera - that is interfering with the those signals. You can wipe these contacts with an alcohol prep pad in an attempt to dislodge any dust and dirt. Clean any lenses used on the camera as well - as dust and dirt on the camera contacts means it's probably been transferred to the lenses, too. Oxidation is a bit trickier to tackle - because the camera is wide open to collecting anything that drops into it. If cleaning with an alcohol prep doesn't solve the problem, I'd contact Nikon support for their suggestions or to arrange for repair.

Good luck!

the lens contacts are probably dirty so,

1. Get a pencil with an eraser on the end, Detach the lens from the camera, hold it so that the lens’ gold contacts are pointing down and lightly erase their exposed surface, cleaning them of anything that may have coated them making the contact poor.Lightly dust the contacts with a small paintbrush to remove any loose dirt.
   
2. Do the same thing with the gold contacts inside the camera body. This is a little more difficult.: just hold camera so lens opening points down so no gunk falls in. Erase lightly.Use a lens cloth or paint brush to remove dirt.
3. PLEASE REMEMBER TO KEEP THE CAMERA POINTING DOWN, AND THE SAME WITH THE LENSES AND O0NLY GENTLY RUB THE CONTACTS TO PREVENT DIRT INGRESS INTO THE CAMERA OR LENS
   

Of course, lenses are very sensitive, and require clean rooms (dust-free) to fix them, and then tools to recalibrate them.

Some obvious points would be to make sure the lens setting is not (A)uto instead of (M)anual.

I'm sorry to say that after trying to blow air (carefully) in the cracks while turning the dials might assist, clean the contacts on the opening of the lens.

After these things have been done. You'll have to find a service center to have it repaired.