Regarding the PHP notices, it would appear that something is broken in your database. It claims there is a backup profile with no ID and no name which is not possible. This is something we can try to fix in your database if you are a subscriber.
Regarding the database table exclusion, you do not need to double click on the icon. You need to single click. When you double click the second click is ignored.
There is a reason I decided against multiple selection lists back in early 2010, after trying to implement the interface that way. A multiple selection would require you to CTRL-click (or CMD-click on a Mac) on each item which is far less practical, especially given the fact that you would need two lists for Exclude This and Exclude Data. Trying to correlate two multiple-select lists is frustrating and error-prone even for me, on a site where I could recite the table names by heart. Doing so when the two lists won't have the same number of items (some database items have to be forcibly excluded in some way, e.g. temporary tables from both and VIEWs only in Exclude Data as they are stored SELECT queries) is borderline torture. Add the fact that a mis-click without holding down CTRL / CMD will clear all selections but the one you just clicked, something which can easily happen with a laptop trackpad as I found out the hard way during my experimentation, and you know exactly why all those years ago I chose to create a different, more streamlined interface to avoid multiple-select lists. Moving back to multiple-select lists would be a massive downgrade.
If you want to exclude multiple tables which all start from the same common string, let's say all tables whose name starts with #__foo (remember, #__ is the common database table name prefix), then yes, the Professional version allows you to use the RegEx Database Table Exclusion feature. In this case you would type /^#__foo_/ as your filter. If you want to exclude all tables which do not belong in your current Joomla installation —what I assume is what you are trying to do— you just need to create a filter for !/^#__/ which reads as exclude every tables whose name does not start with the database table name prefix configured for this site. No more clicking a ton of table names, no more having to redo that every time the number or names of the other tables changes. These, and solutions to other common use cases, are given in the documentation. If you can't figure it out, you can tell us which tables you want to exclude and we'll tell you what to do.
Nicholas K. Dionysopoulos
Lead Developer and Director
🇬🇷Greek: native 🇬🇧English: excellent 🇫🇷French: basic • 🕐 My time zone is Europe / Athens
Please keep in mind my timezone and cultural differences when reading my replies. Thank you!
