Hi , i have installed Guest order View module and its working fine , at first i got the mail .php error , however is instructed in comments section it got resolved, but i am getting an error in viewing the order i am attaching screenshot of the error please have a check. thank you in advance.

Any one can help me on this please???

It looks like your Journal2 template is being modifying the same file that OrderSuccessPage is trying to modify. I suppose that if you disable the modification coming from Journal2, the module should start working as expected.

Hope this helps!