About File Preview Failures
Our current document preview solution is based on Microsoft’s online document preview service.
Why Does File Preview Sometimes Fail?
Preview failures or display issues are mainly due to limitations of Microsoft’s preview solution. Compared to locally installed Office software, browser-based previews are less powerful and may not support certain complex document formats, such as advanced layouts or formulas.
If a specific file cannot be previewed but other files display correctly, it is generally not a service issue. Since this preview capability is fully provided by Microsoft, we currently cannot make any adjustments to it.
Our Commitment
We guarantee the following:
- As soon as Microsoft resolves these preview limitations, we will immediately upgrade the related components—no delays.
- If a better solution becomes available to replace Microsoft’s preview service, we will switch to it promptly.
Currently, over 99% of documents can be previewed successfully. If a file cannot be previewed in our platform (HAP), it's likely that the same issue would occur in other systems using Microsoft’s preview service as well.
In terms of recognition rate, success rate, and conversion performance, Microsoft’s solution remains the best available option.
What Can You Try If Preview Fails?
While we cannot guarantee success, here are a few suggestions you can try:
- Save a new version of the file and upload it again.
- For Excel or Word files, try removing complex formulas and keep only raw values. Some formulas may cause preview errors.
- Avoid enabling “Online View Only” if possible. If preview fails, users will at least be able to download and open the file locally.