I was downloading an app from Ailurus. I decided that I did not want that app, but I would wait for it to end. A light blue dialog box had appeared with a java statement to agree to. I couldn't find a place to agree or a box to tick. But it didn't end or finish up. Sometimes a box like this seems to disappear eventually, but sometimes the dialog box is there an hour or more later. I have just cancelled out the terminal heretofore, but got locked out of synaptic and the files. Usually, just restarting the computer took care of this. But several times, I have so hopelessly messed up my files in this way, or just by mistake, or trying to agree to or get the dialogue box off that I had to re-install the whole of Ubuntu and this took quite some time.
Is there any way to correct a file when you have messed it up so badly in downloading that even "dpg --configure -a" will not correct the issue? I once did this also in downloading an update of Exaile and had to completely re-install Ubuntu, and there were other cases. Would Purge PPA work, or is there a simpler way than just re-installing every time I make a mistake in downloading? I would be most appreciative of any suggestions.