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link to an Alias in the DL-Script but it tells me that it isn't
found in the Database.
The Aliases are Case-Sensitive.
If your Alias is "TeStAlIaS" then you have to link exactly
to that and not "testalias".
Also if you're using a space in the name of your alias you should replace
it with an underscore when linking to it. Example: Your alias is "My
Alias" - link to it using "../dl.pl?My_Alias".