need a utility to edit powershell PS1XML files more easily

hi friends

as I mentioned in my earlier threads I'm going to create new PowerShell formatting files (PS1XML) to customize the output of some common Cmdlets for example Get-Childitem and so on.

I've encountered a problem. I've created a copy of  "PowerShellCore.format.ps1xml"& edited the new file. but finally when I update-format data, I encounter the following error:

I don't want you help me resolve this error. I want to ask something else:

the error tells that I have some mistakes in my editing inside that PS1XLM file.

also maybe I encounter such problems later again.  since I am not very familiar with XML, is there any simple Application to edit XML files more easily & to correcting our mistakes?

I mean is there any Application that simply find the false codes inside xml files & outline them & suggest what change should we make to correct the file?

thanks a lot