Inventor Error. Cannot modify

[craigboez]

Sounds like a Vault related error. When you first create your project you'll need to choose between a single user project or Vault based. If you choose Vault it'll enforce file permissions designed to allow multiple users to collaborate. Might want to check there. You can also maybe just check the part out so you can edit it. There is a Vault tab with several options, including Check Out and Check In.