在foreach循环中退出的PHP脚本没有错误，由echo long字符串解决

I'm currently stuck on a somehow weird error in a PHP-Script that is driving me nuts for two days straight now. Before you ask, I already did some research on the topic an found a few Threads, but none of the suggested answer worked in any way :( Therefore I wanted to give a detailed description of what is happening (or failing :D) and how it can be worked around hoping anyone of you will have some great idea :)I'm currently stuck on a somehow weird error in