Using uBO 1.11.5rc0 Webextensions version under Fx55 Nightly 64 bit.

After clicking on the 'Backup to file' button to save my settings I do not get a dialog asking me where to save the file. The backup temp file that Fx creates is in my Windows Temp folder. This is an interim file Fx creates named something like xxxxxxxxx.fileextension.part. If the dialog was presented to me and I saved it it would have been renamed to uBO's proper backup settings naming convention.