Getting 0x80070057 in Windows Update when trying to update to Build 17686

Windows Update tries to install the update as usual, and then after a while, I get a download error 0x80070057:

At first I thought this was a storage issue (I had 3 GB of free space at the time), so I moved some of my 'heavy stuff' like anime and software setups to my private LAN file server, and now I have 14.9 GB of free space.

Please help me solve this issue. I really want this build.

Try the Windows 10 Insider Preview Build 17704 via Windows Update. It includes a fix for error 0x80070057

General changes, improvements, and fixes for PC

• We fixed an issue that could result in seeing a 0x80070057 error in Windows Update when upgrading to the last few flights.