If you are reserving a feature in your options file for a user, please be aware that username of the user executing FLEX enabled application is case sensitive.
For example, by having the line below in adskflex.opt file would reserve AutoCAD C3D 2010 for user david.
RESERVE 1 73700CIV3D_2010_0F USER david
Now if David’s account was created with uppercase letters , when David logs on onto his system license server will see him as DAVID and will not issue the reserved license, but a new license while keeping the reserved license for user david.
This issue can be resolved in the adskflex.opt options file by also including the option for GROUPCASEINSENSITIVE. This option will make the list of users not case sensitive and thus avoid the above issue.