list/template=longtable needs not only the longtable package but also array

[FrankMittelbach]

Without array it errors with

<argument> \TemplateName 

l.30 \newpage
               \ac{lol}
? 

and only then with

./3-0-11.ltx:30: Package acro Error: The template `' needs the package `array' 
loaded on line
(acro)                30

Type <return> to continue.

which also explains the first error.

[cgnieder]

Thanks, fixed! :)