Hi ​@michuk,

You said sometimes it doesn’t work.
Have you noticed anything specific about the file name when it doesn’t work, like does the original file have special characters or anything or does the new name have something different in it compared to when it does work?
Do you get any errors when it doesn’t work?

The error is: 

The workflow could not update the item, possibly because one or more columns for the item require a different type of information.

Hi michuck,

This error means you are trying to update the column with the wrong data type.
For instance, you may need a string, but you are using an integer, etc.  Make sure that the variable you are using to update the file name is of the correct data type.

Is the Name column a single line of text?

Is the Email subject a single line of text?

Is there a characters the email subject is around 199 characters. 

It working for 89 characters.

​@michuk, It sounds like you have found your issue.
If the text is too long in the subject an error occurs.

​@SimonMuntz 

Do you know any other ways of actioning?

Hi ​@michuk,

As you know, the error occurs when the string is too long; you could check its length and truncate it if it’s too long before doing the update.

As the string is too long, I guess that it is being passed as multiple lines of text instead of single lines of text. This is just a theory. As we are renaming a file, the issue could be the file name length.