Loom “Upload Failed” after Long Screen Recordings

An abrupt “Upload Failed” notification following a lengthy screen capture cuts off your distribution pipeline immediately on both the Loom desktop application and browser extension. This stalling behavior indicates a communication breakdown between your local disk cache and Loom’s ingest servers, rather than a broken audio-video recording engine. Resolving it requires retrieving the raw media parts from your machine’s isolated storage directory and pushing them through a manual assembly path.

Fast-Fix: The 45-Second Solution:

Loom “Upload Failed” errors after long sessions are caused by local cache file indexing drops, disk space starvation, or HTTP session token timeouts during large multi-gigabyte multipart uploads. To fix this instantly, do not close the app; navigate to Loom’s Preferences, click Account, select Check for Stuck Uploads, or manually extract the temporary .loom raw files from your local app data directory for web-portal uploading.

Quick Logic Snapshot

• Severity: Operational / Critical (complete block on sharing and processing freshly recorded media files).
• Impact: Single Endpoint Node / Individual User Profile.
• Primary Cause: Network connection drops or authentication token expirations while transferring large, multi-gigabyte file chunks.
• Rare/Security Cause: High-volume inspection filters or local data loss prevention (DLP) agents blocking prolonged background HTTP PUT requests.

Low Risk vs. High Risk Scenarios

The potential for total data loss hinges on how you interact with the software interface immediately following the failure notification:

• App Kept Open with Error Banner Displayed: Lower Risk. As long as the Loom application remains open and running, the raw, uncompressed recording blocks sit intact inside your workstation’s hidden temporary folder. The asset can be re-queued or pulled manually out of disk storage.
• Closing or Force-Quitting the Loom Process: Moderate Risk. Forcing the software application to close drops the active file indexing pointers. While the raw video blocks usually remain on the storage drive, the internal metadata manifest mapping them together may wipe, requiring file recovery tools.
• Logging Out of the Loom Client Entirely: Critical Failure. Logging completely out of your user profile triggers an automated application maintenance script that purges the local temporary cache folders. This action can permanently delete the raw recording files beyond recovery.

What This Means (The Protocol Layer)

When you record a short video clip, Loom streams your audio and video components to the cloud in real time. However, during an extended multi-hour recording session, the app creates an internal buffer loop, writing large uncompressed chunks directly onto your physical hard drive to protect against network drops.

Once you click stop, Loom breaks this massive file into smaller, numbered chunks and begins an automated multipart upload sequence. If your internet connection jitters, or if the server’s security token expires before all the pieces arrive, the data pipeline stalls out. The cloud server drops the incomplete upload chain, and the desktop client displays the generic “Upload Failed” alert banner.

Probability Breakdown

• Authentication Token or Session Expiry (50%): The long duration of the session causes the security handshake token to expire mid-transfer, making subsequent chunk uploads look unauthorized to the receiving server.
• Workstation Disk Space Starvation (25%): Your local storage drive drops under 10% capacity during the final rendering pass, halting the app’s ability to assemble the final cache container.
• Upstream Network Packet Depletion (15%): Router buffers or local wireless networks dropping connection packets during prolonged, high-bandwidth uploads.
• Antivirus Heuristics Interruption (10%): Security scanning engines mistaking the rapid, continuous writing of temporary file segments for malware behavior and locking the active directory.

Logic Escalators

• Recording at Max 4K Resolution: Capturing video at 4K resolution vastly increases the volume of data generated per minute, accelerating local storage usage and increasing the risk of cache errors.
• Using Wi-Fi Connections on Corporate VPNs: VPN encapsulation combined with standard wireless connection drops creates severe packet lag that easily disrupts Loom’s multipart transfer streams.
• Heavy Concurrent Drive Tasks: Running intense local operations, such as disk defragmentation, heavy database updates, or background game downloads, starves the drive speeds required to process Loom’s temporary cache.

If Ignored: 1 Hour → 1 Day → 1 Week

• 1 Hour: The video stays locked on your local drive, unusable and invisible to team members waiting on the shared production link.
• 1 Day: Accumulating system logs and background processes can lock up the loose temporary files, increasing the risk of metadata corruption.
• 1 Week: Automated operating system cleanup scripts or storage management utilities may flag the orphaned video fragments as junk data, permanently purging them from your machine.

Confused With / False Positives

• Local Initializing Loops: If the app hangs before you even hit record, your machine is experiencing a launch block rather than an upload failure. This behavior is covered in Loom “Desktop App” stuck on “Initializing”.
• Chrome Extension Extension Drops: If the failure occurs while using a browser extension, it’s often an isolated browser tab issue. For browser specific crashes, see How to Resolve: Loom “Chrome Extension” crashing during Capture.
• Enterprise DLP Hard Blocks: If your company security system drops a permanent block on Loom data streams, look into the security policies detailed in Loom “Screen Recording” blocked by Corporate Security (DLP).

What To Do Right Now

1. Keep the Loom application open; do not sign out, close the window, or reboot your workstation.
2. Click the gear icon to open Preferences, select the Account tab, and look for a dedicated Check for Stuck Uploads button to force the app to re-verify the data pipeline.
3. If the automated recovery tool fails, open your operating system file browser and navigate to the hidden local cache directory to secure your raw recording files:
   • Windows: %LOCALAPPDATA%\Programs\Loom\desktop-local-storage
   • macOS: ~/Library/Application Support/Loom/desktop-local-storage
4. Copy all files with a .loom extension or raw numbered folders out to a secure backup directory on your desktop, change the extension to .mp4 on the largest file fragments, and test if they play in a standard media player before trying a manual web upload.

Immediate Intervention Flags

• The host operating system fires an urgent warning alert stating “Low Disk Space on Local Disk C:” or equivalent storage volume.
• The application interface shifts from an upload failure notice to a hard authentication block loop, asking you to sign back in.
• The raw temporary directory files show a size profile of exactly 0 bytes, which points to a deeper local save failure covered under How to Resolve: Loom “0 byte” file size for local downloads.

What a SysAdmin Will Check

• Network Log Audit: Network engineers will look at firewall traffic history to check for dropped HTTP 403 Forbidden or 504 Gateway Timeout codes targeting Loom upload buckets.
• Disk I/O Profiling: Tracking whether local endpoint security software is throttling disk write privileges inside the application data folders.
• Session Lifetime Policies: Verifying if internal single sign-on (SSO) configurations are systematically terminating active user web tokens after a set number of hours.

Administrative Scope

• Classification: Minor to Moderate (User-level recovery or local file isolation).
• Mitigation Policies: For teams that routinely record long product reviews or training guides, administrators should deploy configuration scripts that direct Loom’s local storage path onto uncompressed internal drives with a guaranteed 50GB storage buffer.

Related Logical Handshakes

• If your long captures manage to upload but lose video synchronization or skip frames under heavy loads, review the system steps in Troubleshooting: Loom “Frame Rate Drop” during Software Demos.
• If your finished long-form video saves but renders without any of your microphone or system sound tracks, look over the audio routing steps in Troubleshooting: Loom “Audio Only” Recording when Camera is On.

Operations Summary

A Loom upload failure after an extended recording session is almost always caused by a broken network handshake or a disk capacity bottleneck rather than an unrecoverable video file corruption. Never close or log out of the software when an error hits, as this can delete the active cache directory. Instead, use Loom’s built-in stuck upload recovery tool or browse directly to your workstation’s hidden local storage directory to pull the raw media fragments out safely for manual publishing.