Some users of RapidWeaver 7 have been experiencing an error when trying to save a document — "The document "X.rw" could not be saved".
This is due to RapidWeaver reaching the maximum number of file-system resources it's allowed (this is due to it essentially leaking kernel resources).
You can run the following command in Terminal.app to see if you're close to the limit of 255: lsof -c ScopedBoo
Look at the last line of the output:
ScopedBoo 343 Dan 89r DIR 1,4 204 18547828 /Users/Dan/Desktop/Bunny Blog.rw
In the above example, it's at 89r. If you're approaching 255r we recommend you restart your machine to reset this to 0r. Each future save will increment this number, regularly restarting your machine between each RapidWeaver session will work around this issue.
We are still investigating ways of fixing this issue, but believe it's a system issue that Apple needs to fix. The above should be considered a temporary workaround until we find a way to work around the system bug.
Note: We've filed a radar (a big report) with Apple on this issue here: