Checked: 23 October 2026. Clicking Attach in Thunderbird opens no file picker? If the previously used folder is no longer available, the symptom matches bug 2077590. The manufacturer lists a fix in Thunderbird 158 and 153.5.0esr. This guide helps home users and small IT teams investigate without deleting messages or recreating an account. [1][2][3]
Identify the right symptom
This concerns adding a local file to a new message when the picker never appears. A renamed or removed folder, disconnected drive or temporarily unreachable location is a sensible diagnostic question, not proof of the cause on your computer. Opening a received PDF, a server rejecting a message and attachment size limits are different problems. The tracker marks 158 and ESR 153 fixed but ESR 140 affected; that is not a blanket compatibility promise. [3]
Preparation and recovery
Record the operating system, full Thunderbird version, installation source and ESR or Release channel. Prepare a small, non-sensitive text file in an accessible local folder. Use a new message with no recipient and send nothing. Before updating, locate the profile through Help → Troubleshooting Information, close Thunderbird completely and copy the profile folder to protected backup storage. It contains credentials and private mail. An existing installation or mail server is not a substitute for this backup; check that the copy is complete and readable. [5]
Five diagnostic steps
- Document the symptom: open an empty message with no recipient and activate Attach. Record whether no dialog appears or a dialog opens with a different problem. Repeat at most once; repeated clicking does not establish a fix.
- Check the location separately: if known, open the last used folder in the file manager. If a network drive is disconnected or removable storage unavailable, compare with the prepared local file. Do not change sharing, permissions or security controls, or blindly recreate removed folders.
- Try a temporary alternative: drag only the harmless test file from the file manager into the compose window. Check its name and size in the attachment list. The bug report describes drag-and-drop as a working alternative, not a repair of the picker; it may not suit every assistive-technology workflow. Do not force an inaccessible method. [3]
- Install an approved update through the existing distribution route and fully close Thunderbird or use the offered restart. For a manually installed desktop copy, Help → About Thunderbird is the documented check; Linux distribution packages update through that distribution. Managed devices follow IT procedures. Do not install a second edition over the first or switch channels solely for this problem. [4]
- After restarting, read the version again. In a new message with no recipient, select the local test file through Attach. Explicitly navigate to the documents folder if the starting location is unsuitable. Verify the attachment list and close without sending. Compare the original location only afterwards.
Choose the correct version and channel
158 and 153.5.0esr are the documented fix releases dated 13 October, not necessarily today's preferred update targets. Manufacturer notes for Release 158.0.1 and ESR 153.5.1esr are dated 20 October. Choose the currently approved maintenance release in your existing channel and an edition compatible with your system. A Release-channel fix does not justify an unreviewed ESR migration or downgrade. This initial procedure does not require changing mail.compose.attach.dir. [1][2][6][7]
Verify and escalate
Pass criteria: after a full restart the picker opens, the test file can be selected and it appears correctly in the attachment list. This does not verify delivery or every network location. If only the local file works, ask IT to investigate the original path. If the local picker still fails, report the version, channel, operating system, exact steps and alternative-method result. Do not publish passwords, real attachments or complete private profile paths. Do not start by cleaning profiles, deleting accounts or reinstalling. If the update introduces problems, stop and preserve the backup; using an older program is not automatically a safe restoration.
Context and sources
A source-based diagnostic guide, not our own Thunderbird test or a guarantee for an individual fault. The order of checks and acceptance criteria are editorial recommendations. No affiliate links or purchase recommendation. The topic reflects current manufacturer fixes, not a claimed search boom.