Solution: In the debugger view I must have missed that on the left hand side you can see the function that calls the error handler. This narrowed it down to the SD card initialization. Commenting out MX_SDMMC1_SD_Init in main "fixed" it, but this would need a proper solution later if using the SD card. As well, if using CubeMX to regenerate the code, will need to remember to comment it out again.

Made blink work once, now unable to get anything to run on the STM32L496. Using debug mode and pausing the program, it is stuck in Error_Handler. The code in main loop is commented out, and everything is as it was using the STM32CubeMX to set up the board using their template.

In STM32CubeProgrammer, tried a mass erase. There was no change.

In fault analysis, it says DIV_0_TRP was enabled. When running fault analysis again, the same error had disappeared.

Unsure the source of the error. Perhaps something with STM32CubeMX?

Further debugging is needed