What version of ENVI and on which OS?
In ENVI 5.4/IDL8.6 and the first version of the new licensing there was an issue with switching mac addresses. This was resolved in the newer releases although on Mac and Linux, it can occasionally return.
You can try clearing the C:\Program Files\Harris\license\flexera and C:\Program Files\Harris\license\flexera-sv directories as well as deleting the device.id0. Then try reactivating the license.

ENVI 5.5.1
W10 Enterprise 64bit
i ended up doing a full uninstall and reinstalled and it worked.
But the software team have just deployed it to a lab computer and they got that error - so i will try your suggestion!

I'm having the same issue trying to open ENVI 5.5 (64-bit) on Windows 10 Enterprise:
"Unable to license IDL Runtime".

When I try opening ENVI 5.5 + IDL 8.7 (64-bit) I get a bit more information:
Unable to license IDL.

Reason:
CLLAcquireLicence: [1,111,1,1[11111111,111,11111111]] Generic communications error.

[1,111,1,1[11111111,111,11111111]] An HTTP error was returned from the server. HTTP response code said error (404) : Generic communications error. (code : 1946157064) (cll_internal.cpp : 1488)

I've tried reinstalling ENVI but still get the same error.
I've tried deleting the files Mari suggested but still get the same error.

Using Harris License Administrator when I enter the server name and port number and press connect, it says Successfully connected.


Any ideas on how I can fix this issue?
Colleagues are able to run ENVI using the same license server and I was able to connect a couple of months ago when I last tried.

After it shows it connected to the license server, go to View Licenses. Does it show that an ENVI+IDL license is available? You can also look at the features to see if they are available.

Yes, the licence is available.

Feature Version Expiration Count
*ENVI Desktop 5.5 permanent 1
*ENVI Headless 5.5 permanent 1
*ENVI Headless Process Engine 5.5 permanent 4
*ENVI Headless Task Engine 5.5 permanent 1
*ENVI LiDAR 5.5 permanent 1
*ENVI Task Engine 5.5 permanent 1
*IDL 8.7 permanent 1
*IDL MPEG2 Read 8.7 permanent -
*IDL MPEG2 Read Process Engine 8.7 permanent -
*IDL MPEG2 Read Task Engine 8.7 permanent -
*IDL Process Engine 8.7 permanent 12
*IDL Runtime 8.7 permanent 1
*IDL Task Engine 8.7 permanent 1
*IDL Video Read/Write 8.7 permanent -
*IDL Video Read/Write Process Engine 8.7 permanent -
*IDL Video Read/Write Task Engine 8.7 permanent -

It is hard to say what communication issue may be going on. Perhaps your firewall is blocking communication back to the license server? You might want to contact your license administrator with this issue so they can work directly with Technical Support.

I'm experiencing the same problem with version 5.5.2 for Windows. I already tried deleting the license folders as suggested but i still got the same message

I am having the same problem on a Mac running Mojave 10.14.4. It was working either this week, and now it does not. I also tried deleting those files and reactivating, but no luck.

Just a note that the "Unable to License IDL Runtime" error with ENVI is 100% a generic licensing error. If you have access to an IDL license, try launching IDL Command Line to get a better error message that will assist with troubleshooting.

I guess there has not been a resolution here. I am having the same problem with a particular machine ( Have several that run ENVI without a problem).

On the machine that is failing, I have uninstalled and removed the Harris directory and reinstalled. Rebooted.

Tried to run envi, envi+idl, idlde, and idl command line and all fail simply saying 'Unable to license IDL Runtime'

The license manager connects to the server and I can view available licenses in the gui. I can ping the license server without a problem.

I have tried everything I can think of to no avail. The only thing I can think of is something is wrong in the registry?