Not enough download bandwidth left
The file page blocks download because remaining rolling bandwidth for this viewer’s tier is less than the file size. Product text does not always include a buy-traffic CTA (see the buy-package sibling when packages are available).
Why this happens
usedBytes + fileSize > effective ul2_bw_mb_* in the current window. Upgrade may still help if a higher tier has more bandwidth. Enforcement at mint/stream can use Bandwidth exceeded family messages.
Diagnose and fix
1. Wait for the bandwidth window to roll, upgrade, or buy traffic.
2. Admin: raise ul2_bw_mb_* / window days under Download bandwidth.
3. Per-user override if appropriate.
4. Distinct from max download size and per-user download count limits.