Red Triangle and I can only shift into neutral and park

I had meniscus and ACL surgery on September 1st and have only been able to drive my 2007 for very short lengths of distance and time because of my surgery. This past Wednesday, I tried to start my car, and the red triangle turned on. I ran the OBD, and only codes concerning my air conditioner returned. My air conditioner hasn't worked for a long time, so that didn't bother me. I disconnected and reconnected the battery, and I was able to drive it, and I did drive it for 45 minutes. The hybrid battery even charged up to about 80%. However, when I turned off the car in my driveway, I ended up with the same original issue that I could only shift into park and neutral. With a friend's help, I tried to disconnect and reconnect the regular battery and the lithium-ion battery for 25 minutes, but I still have the same issue. I reran the OBD test after I disconnected and reconnected both batteries, and it didn't return any codes. Any suggestions are welcome.