Garage door - sunlight & garage door sensor
My Genie suffered the same issue, sunlight "blinding" the system.

After reading all the "fixes", it occurred to me that the one simple remedy would be to simply reverse the devices, putting the receiver pointing away from the sunlight instead of into it.

The opener doesn't care which way it's laid out; it's totally arbitrary, at the whim of the installer.

The wiring on the Genie is very simple, with two leads to each device. This can be done in either of two ways: "home runs", (a pair of leads to each device), or a "loop", (one lead going to one device, then looping over to the other one). Both circuits are electronically the same. The red wire connects to the white with black stripe and the white wire connects to the white-only wire. 

It took ten minutes to do, and I didn't have to build any boxes or use any toilet paper tubes. Hope this helps.