EOS Rebel T7 says EF 75-300 isn't compatible

[outlawbaby1620]

for some reason with this lens my camera keeps telling my the contaact len err code one is it beacue this lens isnt compatable with my rebel t7

[deebatman316]

The lens is compatible with your camera. The flex cable inside the lens has likely failed. This lens is very poor optically. It would be much better to replace it than repair it. A good replacement lens would be the EF 70-300mm F/4-5.6 IS II USM lens. Or another good option would be the EF-S 55-250mm F/4-5.6 IS STM lens. These are great replacement options. The cost to repair the lens is more than what the lens is worth. Also this lens uses a very old and slow AF motor called Micro Motor. This AF motor was first released in 1993. The 2 lenses I recommend as replacements use faster AF motors and include IS (Image Stabilization).

[shadowsports]

Cheers Demetrius.  Great recommendations.  Also both of these lenses have IS which his current lens does not.  

[ebiggs1]

Not so fast cowboy.

 If you have access to a second lens and/or camera try different lens on your camera to see which component has problem. You must determine which is at fault and not simply assume it is the lens. Also remove the battery and make sure it is fully charged and in good working nick.