When you work on a website over time, you’ll often need to update Nicepage, switch between devices, or move projects between Desktop, Online Builder, WordPress, or Joomla. While we fully support these workflows, problems can occur if different editor versions or project files are used incorrectly.
Many compatibility issues are caused by changes in the internal project structure introduced in newer versions of Nicepage. As a result, projects saved in newer releases may not work correctly in older ones, and some import or recovery attempts may fail if the wrong files are used.
This guide explains the most common version compatibility issues, project corruption scenarios, and recovery methods to help you keep your work safe.
Learn more about Backup / Import Projects, Application Preferences, and follow the latest changes in the Release Notes.
Problem 1: A Project Opens in a New Version but Not in an Older One
One of the most common compatibility issues occurs when a project has been opened and saved in a newer version of Nicepage. When this happens, the project is automatically updated to the latest internal format. Older versions of Nicepage cannot read this updated structure, so the project may no longer open or become read-only.
This also applies when a project is edited in the Online Builder, which always runs the latest available version of Nicepage.
Solution
To avoid compatibility issues:
* Keep working on the same Nicepage version throughout a project.
* Avoid opening important projects in newer versions unless you plan to continue using them.
* If you use a Lifetime License, you can disable automatic updates.
* Create a manual project backup before installing a newer version.
If the project has already been opened in a newer version, check whether Backup on Update was turned on in Application Preferences. If so, Nicepage has created a backup of the project before the update, so you can restore the previous version.
Learn more about Application Preferences and Backup / Import Projects.
Problem 2: Project Content Is Missing or the Project Became Corrupted
Sometimes users report that pages suddenly disappear, layouts become damaged, or projects behave unexpectedly after a crash, failed update, or interrupted save.
This may happen because:
* the application closed unexpectedly while it was saving
* the project file got damaged
* synchronization software interrupted file writing
* the project was overwritten during an update
Solution
The first thing to check is whether a backup is available. If Backup on Update or automatic backups were enabled, restore the project using Restore Site from Backup or recover it from the Backup Folder configured in Application Preferences.
If no backup is available:
* look for previous copies in your project folder
* restore a manually exported project archive
* avoid continuing to edit the damaged project until recovery attempts are complete
Regular backups remain the most reliable protection against accidental data loss.
Problem 3: "The Website Cannot Be Updated in Read-only Mode"
Lifetime License users sometimes accidentally install a newer version after their update period has ended. If the project is saved in this newer version, opening it again in the older licensed version may display the message: "The website cannot be updated in read-only mode."
This happens because the older version cannot modify a project created with a newer internal format.
Solution
If possible:
* Restore a backup created before the update.
* Reinstall the latest version covered by your update period.
* Always verify your update period before installing a new release.
For more information about licensing and update periods, please refer to the General FAQ.
Problem 4: "Invalid Project File" When Importing
Another common issue appears during project import.
In many cases, users accidentally try to import an exported HTML website instead of a Nicepage project backup. HTML exports contain website files only; they do not include the project data required by the editor.
Import errors may also occur if project archives get damaged during transfer through cloud storage or FTP.
Solution
Always make sure you are importing a Nicepage project backup rather than an exported HTML archive.
If the project was transferred between devices:
* verify that the ZIP archive is complete
* download the file again if necessary
* avoid interrupted cloud synchronization before importing
Problem 5: Projects Stored in Cloud Folders Cannot Be Opened or Are Missing
Some users store their Nicepage project folders inside cloud-synced locations such as OneDrive, iCloud, Dropbox, or other network folders to access projects from multiple devices.
While this may seem convenient, cloud synchronization can interfere with how Nicepage manages project files. If files are not fully synchronized, temporarily unavailable, renamed, or locked by the cloud service, Nicepage may fail to recognize the project or open it correctly.
Typical symptoms include:
* Projects disappear from the Nicepage Dashboard
* Nicepage cannot find the project folder
* The project opens incorrectly or becomes unavailable
* Recent changes are missing after synchronization
* Project files appear incomplete
The Nicepage Desktop application works best when the active Projects Folder is stored locally on the computer. The default location is usually the Documents/Nicepage folder.
Solution
Do not use cloud folders as the main working location for active Nicepage projects.
Instead:
* Keep the Nicepage Projects Folder on a local drive.
* Use cloud storage only for backups or your exported project archives.
* Before moving projects between computers, use Export Project and import the project on another device.
* Make sure cloud synchronization has fully completed before copying backup files.
If a project was already stored in a cloud folder:
* Check that all files are fully synchronized locally.
* Copy the complete project folder back to a local drive.
* Open Nicepage Preferences and verify that the Projects Folder points to the correct local location.
* Restart Nicepage and check whether the project appears again.
For important projects, keep separate project backups instead of relying only on cloud synchronization.
Problem 6: Imported Projects Cannot Be Restored Properly
Sometimes importing a project from another computer or from an online source may fail unexpectedly.
This can happen if the project was not exported correctly, if online publishing settings conflict with the imported project, or if the project data is incomplete.
Solution
Before importing:
* export the complete Nicepage project
* finish any active publishing operations
* remove conflicting domain assignments if needed
* import the project into a compatible Nicepage version
If you're moving projects between editors or devices, exporting a full project backup is always recommended.
Problem 7: Pages or Theme Settings Suddenly Disappear
Although uncommon, users occasionally report missing pages, empty layouts, or theme settings resetting after unexpected interruptions, failed recovery attempts, or project modifications.
Fonts, colors, or page content may also appear different if the project was restored from an incomplete backup.
Solution
To reduce the risk of data loss:
* save projects regularly
* keep multiple backup copies
* export project backups before making major structural changes
* verify backups before deleting older project versions
Automatic backups can also be enabled in Application Preferences.
Problem 8: WordPress or Joomla Editor Shows a White Screen
Sometimes the editor inside WordPress or Joomla may display a blank page instead of opening normally.
This is usually caused by incompatible versions of the Nicepage plugin, theme, or Desktop application.
Solution
- Keep your Nicepage components synchronized.
- Whenever possible, use compatible versions of Nicepage Desktop, Nicepage Plugin and Nicepage Theme.
- Updating only one component may cause compatibility issues.
- Before updating, review the latest compatibility changes in the Release Notes.
Problem 9: Desktop, Plugin, and Theme Versions Do Not Match
Some users update only the Desktop application while leaving the CMS plugin or theme unchanged. Others update the plugin without updating the Desktop editor.
Different versions may support different project formats or features, which can lead to unexpected behavior.
Solution
- Before starting work on an existing project, make sure your Nicepage Desktop application, CMS plugin, and theme are compatible with each other.
- Keeping all components aligned helps prevent editing and publishing issues.
- Checking the Release Notes before updating is a good way to understand version changes and new requirements.
Problem 10: No Backup Is Available When You Need It
Some users only discover that automatic backups were disabled after a project becomes damaged or cannot be opened. Without backup copies, recovery options become much more limited.
Solution
- Enable Backup on Update in Application Preferences.
- Verify the Backup Folder location.
- Export project backups regularly.
- Store backups separately from your active project folder.
Best Practices for Avoiding Version Compatibility Problems
To reduce the risk of losing access to your projects:
* Enable Backup on Update in Application Preferences before installing new versions.
* Keep automatic backups in the Backup Folder and verify that they are being created successfully.
* Export complete project backups regularly, especially before major changes.
* Avoid opening important projects in newer versions unless you plan to continue using that version.
* Keep Desktop, WordPress/Joomla plugins, and themes on compatible versions and update the plugin and theme together..
* Avoid editing the same project alternately in older Desktop versions and the Online Builder.
* Store backup archives in more than one location, such as an external drive or cloud storage.
* Review the Release Notes before installing major updates to understand compatibility changes.
Final Thoughts
Most project recovery cases are caused by version incompatibility rather than permanent file corruption. Once a project has been saved in a newer version of Nicepage, it generally cannot be opened again in an older release.
The safest workflow is simple: enable Backup on Update, verify that backups are being created, export project archives regularly, and update only when you're ready to continue working with the newer version. These precautions can save hours of work and make recovering a project much easier if something goes wrong.