There is known bugs in MessPHP that will rise when you using configuration: "Base Loop Obfuscate > 1" and "Obfuscate Common PHP Function and Your Own Function = checked/true". here is example code:
The bug will rise if and only if If there is class and in class there is function and in function there is some string with format above, it will break your code and get unexpected error :(
Securing Your Application
There is limitation of MessPHP will not obfuscated some string/value at special place of code. Here is for example
The reason why i dont obfuscated at specific location of your code is if we force to ofuscated at that line, we will get some error and the result of obfuscated will not run :(. Note : because, im not using simple alghorytm to encrypt string like just convert string to hex or octal number.