This can also appear as the error An unknown PNG error has occured.
You may be able to recover the file using ExpandXAR, which you can download here
1) Create a folder and move the expandxar.exe file into it.
2) Copy the corrupted file into the same folder
3) Hold Shift and right-click within that folder > Open Powershell window here
4) Type 'expandxar.exe [name of corrupted file] [new filename]'
For example, if your file is called website.xar, then you would type:
expandxar.exe website.xar website_recovered.xar
5) You should get a message confirming. Try to open the new file now.
If this does not recover the file, then please submit a support ticket and include the following information:
1. The full error message
2. The exact version of the program you are using ( Select Help > About)
3. Include the XAR file as an attachment
We cannot guarantee that we will be able to recover the file. However submitting the problem file will enable us to review the file and try and determine the cause of the error.
All our Designer products has an auto backup feature enabled by default, which will create a backup your open files every 10 minutes (or whenever the program is idle thereafter for this to occur). You can access your backups by going to File > Open Recent > Backups