Canon EOS Lens with error 99

[crystal-lite]

I have a film camera canon 300 EOS and a Digital EOS 20D and I can swap my lenses between

the two. I rarely use the EOS 300 now and use the lenses on the 20D.

However I have Canon zoom lens EF 75-300mm 1:4-5.6 III USM, and now and again when I

attach it onto my D20 (takes both EF & EFs lens) an error message comes up saying error 99.

 

Could this mean it's not compatible or there is a fault on the zoom lens? I have three other EF

lens and have no problem on the D20.

 

Hope you can help, please

[roamingstudio]

Occasionally I had this problem with a Tokina lens. It was something due to the way the camera talks to the lens... I removed the lens, removed and reinserted the battery and everything went well again. Annoying but ive not found a solution yet, apart from possibly dirty contacts.

[vatovec]

I`ve had this problem the other day with the EF 85 f 1.8 and 10D. Unmounted the lens and mounted it again and all was cool again,..

[v.anisimov]

Clean the electrical contacts of the lens with a pencil eraser. Worked for me.

[crystal-lite]

Thanks all for the answers.

Vladimir mentioned about a pencil eraser to clean the contacts. And it's worked! Previously I

could only take one photo and the error message came up, I have now taken lots of shots,

about 30 and works great.

I'm deeply grateful to the answers.