If all else fails, bypass the broken installer entirely. You can manually extract the game files.
Unarc.dll error code 11 The Sims 4 typically indicates a failure during the decompression of game files, often occurring with large installations or repackaged versions . This error is primarily caused by insufficient RAM or virtual memory corrupted installation archives CPU-related processing issues Primary Causes Memory Deficit: unarc.dll returned an error code 11 sims 4