This issue is because an unsupported character is present in the document title. It can be the character that is in the brackets after the word client in the error message.
An example character that this issue can occur with is &.
To remove the character from the title description and re-upload the document, please follow the below steps:
Go to the Content section of the HR software.
Locate the document in the hierarchy.
Click Edit in the top right corner.
Edit the Description field to remove the illegal character.
Click Replace File in the bottom left corner.
Click Save.