Regarding maximum length exceeded

Hey i am doing routing in my pcb file and the power was gone suddenly, i haven’t saved it but i found its auto save when i opened auto save power was one for the second time now iam trying to open both of them are showing same error "maximum line length exceeded’’ what should i do?

Your words read as a mumble jumble and are a bit incomprehensible. I guess you are using some kind of translation? It may help to use shorter sentences.

What is:

Is that opening two different backups, or is it opening Schematic and PCB of a project?

KiCad creates a backup directory, which has multiple backups of a project. You can check if one of the others work.

Can you identify which object causes the “maximum line length exceeded” error? Deleting that object from your files (with a text editor) may be a viable option.

And when do you get this error? ERC / DRC, or when opening a project (file) other?

i am getting error for both backup and original, and iam getting error when i am trying open pcb file

Is your file a big one?

Try making an EXTRA copy of it and opening it with Notepad or other text editor. If the file is not terribly long you might be able to scroll through and look for anything suspicious. But this exercise has a high likelihood of further corrupting the file so that is why I urge you to first make an extra copy.

Another idea: Is there a problem with the filename? Maybe you could try shortening the filename if it somehow ended up being very long.

BTW: The issue you describe is a somewhat-unsung advantage of using a laptop computer. A normal laptop computer comes with battery backup, so power line outages should not cause an immediate crash.