OK, now I understand. Using \n as a new line does not couse the problem (with pluginVersion=1 - with pluginVersion set to null it just displeys \n characters and does not hang).
I used new line that was copied from text file - i copied full text with new line characters from text file. And in that case, application hangs on browser side.This behavior occurse only with pluginVersion=1. When I change pluginVersion to null, browser works correctly and shows new line in text.
thank you for answer - it is clear for me now. The only thing you might consider is to add some validation during modeling. It would prevent browser hangs.
For best results, use the Firefox browser..