Templates troubleshooting and common mistakes
Most template problems come from a handful of easy-to-fix causes. Work through the ones that match your symptom.
"I can't edit this template"
You are probably trying to edit a shared / built-in template, which is read-only for everyone. You can only change the code or labels of templates you own. Fix: duplicate the template and edit your copy (see Building and editing templates).
An image or video is blank in the result
A media parameter can only point to a file that already exists in your library. If the field is empty or points to a removed file, nothing shows. Fix: upload the media first (see Adding content to your library), then pick it in the template field and preview again.
A number is rejected or behaves oddly
Some number parameters have a minimum and maximum. For example, a "left side width" may only accept 1–99. If your value is outside the allowed range it won't be accepted. Fix: enter a value within range.
Editing one row changed or wiped the others
When you edit a list / table field, keep all the rows you want — edit the row you need and leave the rest in place. Removing or blanking other rows removes those items from the result. Fix: re-add any rows you didn't mean to remove, then preview.
The result doesn't fit the screen
Each template has a fixed canvas and orientation (for example 1920 × 1080 landscape). A landscape template on a portrait screen — or vice-versa — will not fit. Fix: use a template whose orientation matches the screen, or duplicate and adjust the design (advanced).
My changes aren't showing on the screen
Saving the content updates it in your library, but devices only show what is in a published playlist. Fix: make sure the content is in a playlist and re-publish that playlist so devices download the new version (see Put a playlist on your screens (publishing)). It can take a moment for devices to fetch the update.
The video template is slow to produce
Video templates are rendered into an actual video, which takes longer than a still image. If you don't need animation, an image template is faster and lighter. Fix: only use a video template when motion is required.
The preview looks right but the screen is out of date
The preview always renders the current values, but a screen shows the last published version. If they differ, you have unpublished changes. Fix: re-publish the playlist that contains the content.
Still stuck?
If a template consistently renders incorrectly even from a clean preview, the template's code or schema may be out of step (a placeholder without a matching parameter, or the reverse). Ask whoever maintains the template to review it (see Building and editing templates), or contact impressBox support.