Get the official JAR
Use your licensed distribution and check the file before running it.
Choose the right distribution
Access links and activation instructions are provided to licensed buyers. Use the purchase channel or customer access supplied with your purchase. Avoid unconfirmed mirrors and redistributed files.
Choose a release for Minecraft 1.21.11. The runnable distribution is a Paperclip JAR, which prepares the server runtime on first use. A plugin JAR, development bundle, test probe, or source archive is not a replacement.
The audited project produces nusa-paperclip-1.21.11-R0.1-SNAPSHOT-mojmap.jar under nusa-server/build/libs/ in a developer checkout. Customer download names may differ. Use the name of the file you actually received.
Check the file
If the official channel publishes a SHA-256 checksum, compare it there:
Get-FileHash -Algorithm SHA256 .\nusa-paperclip.jarsha256sum nusa-paperclip.jarnusa-paperclip.jar is an example local name after renaming the download. A matching checksum confirms equality with that reference; the reference must itself be trusted.
Keep the previous release
Retain your old JAR, version notes, and configuration backup before an update. Do not assume identically named snapshots contain identical builds. Follow the update procedure when replacing a running server.