Do you have MathModelica? The file C:\Users\TAT\AppData\Roaming\Mathematica\Kernel\init.m is the user mathematica initialization file, in my case it contains simply a comment
(** User Mathematica initialization file **)
followed by one empty line. Do you have that file C:\Users\TAT\AppData\Roaming\Mathematica\Kernel\init.m on your system? In your case Mathematica tries to import something from the user mathematica initialization file and use that to extend the $Path
with a path for MathModelica.
The statement
StringReplace[Import[C:\Users\TAT\AppData\Roaming\Mathematica\Kernel\init.m, String], p:(PrependTo[$Path,~~Shortest[Except[ | ]...~~MathModelica~~Except[ | ]...]~~];) :> (* <>p<> *)]
is wrong because the target behind RuleDelayed is outcommented.
You should probably find the originator of that StringReplace statement and correct or remove it. Help can be found here init.m and here WolframSystemSetup.