... tar file was of the right size but corrupt and unrepairable. ...I guess it's better not to rely on the Archive function if a huge file is involved.
Perhaps something like this:
<a href="link to archive thingy">{.if|{.%total-kbytes% <= 4000000 .}|Archive.}</a>
If the list is over 4gb, the word Archive goes missing so you can't click on it.
If it were complex or script or something, quoting is needed, like this:
<a href="link to archive thingy">{.if|{.%total-kbytes% <= 4000000 .}|{:Archive:}.}</a>
Likewise, if the server were busy and uploads bombed it out, there's this:
[Upload-Link]
{.if|{.%connections% < 37.}|<html stuff that defines the upload link>.}
{.if|{.%connections% < 37.}|{:<script stuff that defines the upload link>:}.}
The upload link appears only if there are less than 37 connections (the server isn't overly busy).
Or, there's this:
{.if|{.%connections% > 35 .}|{:{.load tpl|Throwback11basic.tpl.}:}.}
Right before the <!DOCTYPE HTML, and on the Same line. When the server gets busy, a minified template reduces workload.
Edit: Actual examples can be found in my new template:
http://rejetto.com/forum/index.php?topic=12055.msg1064825#msg1064825