We run Creo 4.0 and I just checked and our license files list "Creo 6.0" in the Release column. I don't think it matters what that says - from what I've seen the FlexLM license servers are compatible with the older versions of Creo. The only trouble I've ever had is trying to run a newer version of Creo with an *old* server. That sometimes isn't going to work.
Like Ken said, it shouldn't matter. "Release 8.0" means it's the highest Creo release the license file can support, so you should be fine using it with Creo 3.0, but you wouldn't be able to run Creo 9.0 using this license file.
Just one thing: to be able to use the license with older Creo release, install licenses using lm_*_standard.txt file – that's the one working with older releases. If you use just lm_*.txt (without standard), you'll be locked to use only highest available Creo release (8.0 in your case).
FYI I always use license file containing BORROW keyword. This file allows me to run Creo 3.0 an higher.
Sorry to hijack this thread (kinda, maybe?) but I've been wondering if it is okay to install a later version of FlexLM to support older versions of Creo like 4.0, 3.0, etc. There seem to have been security flaws in many versions of Flexera software. I'm wondering if I should just use the installation package for Creo 8.0 to jump up to FlexLM version 22.214.171.124. Am I asking for trouble, or this okay to do?
1.] FlexLM version 126.96.36.199 is compatible with older versions of Creo like 4.0, 3.0 (I am not sure about 2.0)
2.] I would expect that FlexLM version 188.8.131.52 is compatible with older versions of Creo like 4.0, 3.0, too (although I didn't try)
3.] launch install_license_server.exe to install FlexLM version 184.108.40.206 (do not forget to uninstall previous version)