Legacy Graph API request features removed on all versions

What changed

With v26.0, Meta ignores the pretty and debug parameters, returns a parameter error for date_format and for root GET /?ids= requests, and drops ETag handling. These removals applied to v26.0 calls from July 29, 2026 and extend to all remaining Graph API versions on October 27, 2026.

What it means

Clients that send pretty, debug or date_format, batch reads through root GET /?ids=, or rely on ETag and If-None-Match caching must change those calls before October 27, 2026.