Please try the following.
■Clear your browser cache and cookies
Your browser's cache or cookies may be damaged.
Please read [ How to delete temporary internet files (cache) ], [ How to Delete cookies ] and try to delete your cookies and cache.
After you have finished, restart your browser and try your download again.
■Download using DLsite Nest
* This software is only recommended for operating systems set to Japan/Japanese. [* OCT 2021]
For more details please refer to; "How can I set Windows 10 to Japan/Japanese?"
○With Windows
With DLsite Nest, download, decompression (extraction), and merging are all completed automatically. Just sign in to your DLsite account, select a product from your library, and click "Download",
[ DLsite Nest App Download and Installation ]
If your problem is still not resolved after following the instructions above, please contact us.