Let me clarify between license file and entitlements. The license file is used to start up the Enterprise Dashboard. A new license file will not be required to start up a VSE.
From an usage perspective, you should only use what you have entitlements for. There is not a limit to the number of VSEs in Functional Mode. You can have any VSEs that you want in Functional mode as the entitlement you are using is based on transaction packs.
If a VSE is in performance mode, you
are limited to the number of concurrent VSEs in performance mode that you are defined in your entitlements/contract.
10.4 has been EOS for a little while so if you have an active support contract, I would strongly recommend upgrading to 10.7.2 and working with support for help preparing for the upgrade and once on that supported version helping start the VSE. Here is the
link to upgrade center.
I hope this helps.