For full licensing options you should use the command line, you cannot revoke or reactivate via web. Permissions/ownership are not needed in the /usr/local/fop2 directory. But security restrictions like selinux can cause problems.
Any kind of licensing problem cannot be handled in the forum due to the private nature of activation codes. But I can point you at some of the restrictions and licenses manage that users should know:
if you revoke version X, you can only activate version X or older (not newer)
to upgrade versions, DO NOT REVOKE FIRST, just download and install the new version
if you want to move servers, you must install same FOP2 versions (as you will have to revoke)
if you were planning to upgrade fop2 anyways, then upgrade in the old server, then revoke and install in the new one
If you need to install a 2.26 version over a revoked 2.20 or similar, you will have to email me privately or contact me via the live help for instructions, as I need to know your activation code.
Best regards,