oK, so I'm not exactly sure what caused your specific error, since I'm looking at the original exported CSV from Deckbox, and not the CSV you modified in order to upload on TappedOut.
My only guess is that, when editing it, you somehow got an extra row added at the end? You wouldn't necessarily see such an issue in a spreadsheet program (such as Excel), but if you open it in a text editor (I used Notepad++), look for a line of just commas. I was sorta able to replicate a "line 1564" error in this way, by manually adding an empty row.
You also need to remove the header row that Deckbox has, but considering you had already tried the "ignore errors" checkbox, I'm betting you already did that as well (although you mentioned your inventory going to line 1563, but really, it only goes to line 1562 once the header row is gone, so... double check that!).
The attached file worked perfectly for me on TappedOut. Some notes about going from DB.org to TO.net (in case you hadn't figured these out yet):
I had to remove the oversized commanders as well as the World Champ Deck card, as TO doesn't seem to support them (not that I found). So that's 4 less total count and 4 less unique.
TO also doesn't support the alternate arts in sets like Fallen Empires. If you upload a CSV with 2+ lines of the same card/edition/language/condition that only differ in the Collector Number field, TO will only use the last instance of that card in the CSV. So e.g. you had 3 lines of "1 NM Eng Basal Thrull from Fallen Empires", for a total of 3 Basal Thrulls, but TO only showed 1. So in the attached file, I merged all those lines to show the total count, regardless of alt art. That's 5 less unique cards.
Had you figured out how to deal with foils? TO is weird, in that it *exports* to CSV with a DB-style CSV (with a single Count column and a Foil column that works just like DB's). But for *import*, it requires you to have two separate Count columns (a la Decked Builder -- a normal and foil count). For the benefit of everyone, I'll share what I found to be the quickest way to do this below.
I hope the file works for you. Let me know if you have questions!
Convert Foils (in Excel)
Deckbox defaults to column A being Count, col B being Tradelist Count, and col H being Foil.
Insert a new column next to col B (making the Foil column now be col I), then type the following formulas into the now columns B and C:
Column B:
Column C:
((You can quickly enter the formula into each cell by either a) entering it in the top row and then copying it down, or b) my preferred method, already having all the needed rows in column B/C highlighted, then pressing Ctrl+Enter after typing the formula.))
Then copy cols B and C and paste them right back where they were, except you'll choose "Paste Values" from the paste options.
Finally, delete col A. The new col A is now the Normal Count column, and col B is the Foil Count column.