Complex sentence: Following the opening at the Berlin Hofoper on 7 December 1844, "Ein Feldlager in Schlesien" was given in that city fairly regularly until 1891, but it apparently was never considered for export to other cities in its original version.
Split into simpler sentences: Following the opening at the Hofoper, Berlin on 7 December 1844, "Ein Feldlager in Schlesien" was given in that city fairly regularly until 1891. Successful as "Feldlager" was in Berlin, it apparently was never considered for export to other cities in its original version.