{"version":"2.1.321","anchor":"attachment-filename-validation-rejects-unsafe-characters","canonical_anchor":"attachment-filename-validation-rejects-unsafe-characters","heading":"Attachments with unsafe characters in their names are now refused","tier":"notice","area":"Attachments","scope":"individual","heads_up":true,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.321\/e\/attachment-filename-validation-rejects-unsafe-characters","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.321","markdown":"### Attachments with unsafe characters in their names are now refused\n\nClaude Code now refuses attachment names and paths with disallowed characters and tells you to rename or copy the file\n\n**Unclear.** Which characters count as disallowed is not shown.\n\n**What**\n\nWhen you attach a file, Claude Code used to check only that the file exists, is inside the working folder and is a normal file. It now also refuses file names and paths that contain disallowed characters. The message asks you to give a file name without those characters. If the file really has that name, copy or rename it to a name without them and send that, or correct the path.\n\n**Why**\n\nSome attachments that used to send will now fail with a message until the name is changed.\n\n- Area: Attachments\n- Tier: You'll notice\n- Useful: 2\/5\n- Signal: 1\/5\n- Scope: individual\n- Heads-up: yes"}