When you are using the Package and Deployment tool the following error appears:
"You do not have modify rights"
This stops you from further deploying packages to another environment.
To prevent this error from occurring again, check the security administrators group role to see if the user account has been added in there and also what rights are applied here.
You can find the location for Roles within Users as per the screenshot below:
If the account does not exisit you can add the account in here. After this you should not see the error appear within the package and deployment tool.