Sometimes Captivate 5 fails to open a project file (.cptx). This might have happened due to some corrupt data structure. The preferred way to avoid data loss is to enable project backup in captivate through Preferences (Edit (on Windows)/Adobe Captivate (on Mac) > Preferences > Global > General Settings > Generate Project Backup). This will create a .bak file for your project (from second save onwards), which will contain the previous saved state of the project.
However, you may try out the following steps to recover full data (up to the latest state of the project). If the data files in the project cache are intact, then this workaround should restore your full project.
1) Go to http://blogs.adobe.com/captivate/2010/09/new-utility-for-deleting-adobe-captivate-project-cache-folders.html, download the “dcache.zip” and install the air app inside the zip (as mentioned in the blog).
2) Start the air app and select your “project cache location” using the “Browse” button (the default location is” My Documents\Adobe Captivate Cached Projects”). Now click the “Refresh” button. This will list all the project names for which the project cache folder is available.
3) Check if you can see your project (which is not opening in captivate) listed there. If yes, then double click on that row in the air app, this should display a dialog containing the “Cache Path” as shown in the image below.
4) Now go inside this “Cache Path” folder and inside the “db” sub-folder, check whether the following exist in it:
a) compressed_data (folder)
b) objects (folder, this should contain an objects.cpo file and its size must be > 0 KB
c) uncompressed_data (folder)
d) audio.cpad (file, size > 0 KB)
e) info.cpi (file, size > 0 KB)
f) text.cptd (file, size > 0 KB)
g) thumbnails.cpth (file, size > 0 KB)
If these folders and files are present, then select them and create a zip file. Now rename this .zip to .cptx.
Note that there may be other files/folders inside “db” (e.g. already_in_use.lock, backup_data, etc.). Don’t include them while creating the zip, just include the ones mentioned above
5) Open the .cptx file in Captivate 5.
Note: This workaround may not work always.
In some scenarios the newly created cptx (created in step 4 above) might have some unsaved changes also (e.g. when the project had some unsaved changes and Captivate crashed, you may see those unsaved changes in the cptx sometimes).