Time Machine stuck on 'Preparing Backup', and having stopped and moved "in progress" file to Trash, now Trash won't empty.
My Time Machine stuck on "Preparing Backup". I tried several times. Restarted - still wouldn't do it (even though the backup disk connects and reads is fine). So, having Googled, I followed recommendations to delete the 'In progress" file from the backup disk. So now, it and some previous ones, are in Trash, which means that Trash won't empty because such files are protected by SIP. I gather turning off SIP to get rid of them then turning it back on, might work, but I'm still left with the problem of Time Machine sticking on "Preparing backup"! Any ideas, please?