Unfortunately we are also experiencing this same problem and it is worth mentioning that we never had this problem in pre 2021 releases. The fault is intermittent, and periodically breaks for various Lumerical products. Several of our users have all independently verified that they have configured their licenses properly and have experienced the same problem with the API. It appears not to be license configuring issue from the user but a fault from the python API establishing a connection with the software.
We have observed this issue on both Linux (CentOS7) and Windows 10. I can guarantee that the software license is correctly configured as if we set the license to the incorrect web address, the user is not able to load the GUI (as expected), and neither is the automation API. When the license is correctly configured users may manually open the GUI without issue. The automation API also causes the GUI to open without prompting for a license, however the simulation handle initialization (i.e. mode = lumapi.MODE(), fdtd = lumapi.FDTD()) does not run correctly and the handle to the simulation is not assigned to to a variable in python and subsequent operations cannot be performed.
To further illustrate that the error is intermittent, (and also the fact that the license is correctly configured) please see the following traceback, where interaction with FDTD is fine, but MODE which is configured with the same floating license, opens the GUI but fails to establish a connection with lumapi on Linux CentOS7:
>>> import lumapi
>>> fdtd = lumapi.FDTD >>> fdtd.addrect
>>> fdtd.delete >>> fdtd.close >>> mode = lumapi.MODE Traceback (most recent call last):
File "", line 1, in
File "/opt/lumerical/v212/api/python/", line 1303, in __init__
super(MODE, self).__init__('mode', filename, key, hide, serverArgs, **kwargs)
File "/opt/lumerical/v212/api/python/", line 1076, in __init__
self.handle = open(product, key, hide, serverArgs)
File "/opt/lumerical/v212/api/python/", line 238, in open
raise LumApiError(error)
lumapi.LumApiError: 'appOpen error: \n Failed to start messaging, check licenses...libGL error: No matching fbConfigs or visuals found\nlibGL error: failed to load driver: swrast\n'
>>> mode.addrect Exception ignored in:
Traceback (most recent call last):
File "/opt/lumerical/v212/api/python/", line 1174, in __del__
AttributeError: 'MODE' object has no attribute 'handle'
Traceback (most recent call last):
File "", line 1, in
NameError: name 'mode' is not defined