Troubleshoot rendering failures
This guide helps you fix an adaptation that fails to render. It is for template builders, and for anyone producing adaptations who hits a failed render.
Start with these checks
Before you change the template, work out whether the problem is the template or the content going into it.
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Produce the adaptation again using simple test values, such as each parameter’s own name in its field. If the test succeeds, the cause is in the content or assets you entered, not the template.
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Check that every asset you selected uploaded fully, and that no links are broken. Re-upload anything that did not.
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For video and motion templates, open the failed adaptation and rest the pointer on the Failed status to read the error message.
Common causes and fixes
Each problem below is a common cause of a failed render. Select one to see how to fix it.
Problem: The render fails, or a field renders blank, and a parameter contains special characters.
Solution: use only letters and numbers in parameter names, labels, and values.
Special characters cause three kinds of failure: the adaptation fails to produce; the adaptations list fails to load (square brackets [ ] are a common cause); or the adaptation renders but a field comes out blank (dots or symbols in a parameter’s name).
Remove the characters and produce the adaptation again. For a parameter created in the Extension for After Effects, rename it in the extension, then re-collect the files and publish a new template version. The internal name keeps its original characters even after you change the label, so renaming in the extension is the only fix.
Parameter names, labels, and values explains the difference between a parameter’s name, label, and value.
Problem: The render fails after you paste text copied from another application.
Solution: text copied from a word processor or email can carry hidden formatting the renderer cannot read.
Paste it as plain text instead, then produce the adaptation again.
Most applications offer a paste-as-plain-text option, often Ctrl+Shift+V on Windows or Cmd+Shift+V on macOS.
Problem: The render fails because a source asset is missing, broken, or cannot be downloaded.
Solution: re-link or replace the asset, and make sure any asset referenced by a URL is publicly reachable, because a private or missing link fails.
In the Extension for After Effects, use Find Missing Footage and Collect Files before you re-upload the project, and upload from a fully synced drive, because cloud-sync tools can leave files only partly synced.
Problem: A required parameter has no value, and the adaptation fails or stays in validating.
Solution: fill every required field before you produce the adaptation. If a field should not be mandatory, make it optional in the template.
Problem: The render fails with an error about encoding, such as Output generation failed while encoding.
Solution: this often appears after you edit an older template. Check the template’s custom thumbnail: if the thumbnail is set to a custom reference, every output size needs a value. A single size left without a value fails every render.
Problem: The thumbnail is blank or wrong after you shorten a video.
Solution: the fallback image still points to a frame beyond the video’s new end. Move the timeline to the frame you want, reset the fallback image to the current time, and publish a new template version.
Problem: The render fails referencing missing footage, and the project uses an image sequence.
Solution: the Extension for After Effects does not support image sequences, even when the layer is turned off. Remove the image sequence from the project, then render again. For further information, refer to Known limitations.
Problem: A 3D template fails to render.
Solution: the Cinema 4D renderer is not supported. In After Effects, open Composition Settings and set the 3D renderer to Classic 3D.
Problem: The render fails on a video file that is unsupported or too large.
Solution: convert the video to H.264 in an MP4 container, and keep it within the supported resolution. Known limitations lists the supported codecs and resolution limits.
Problem: The render fails with an error about cleaning the directory, such as Failed to clean directory after last render.
Solution: a previous render left the machine part-way through cleaning up, and your render is usually fine. Wait about 30 minutes, then produce the adaptation again.