Problem updating MacBook Air M1 from Sonoma 14.4.1 to Sequoia 15.5

When attempting to update, the following message appears:

“The software update could not be personalized. Please try again.”

“An error occurred while downloading the selected updates. Check your internet connection and try again.”

What I’ve tried:

• Installation via automatic update – error message appears.

• Tried using the installer file from disk – same error message.

• Installation in safe mode – same error message.

The internet is connected, the power cable is plugged in, and there is over 40GB of free space on the disk.

Please help – what could be causing this error and blocking the update?