Complex sentence: The play was hailed as "the most important and successful night" in Hebbel-Theater in Berlin that "it was impossible to get the audience to leave the theatre" at the end of the performance.
Split into simpler sentences: The play was hailed as "the most important and successful night" in Hebbel-Theater in Berlin. It was said that "it was impossible to get the audience to leave the theatre" at the end of the performance.