Please find the dll file in question (its default location is C:\Program Files (x86)\AIT\AnyLexic 2.0\fb\udf). First of all, please make sure that the file itself and the folder it is in are not compressed.
Then right-click, and select "Properties >> Security". You will see a list of permissions for different user groups. Please make sure that all groups have at least the "read" and "read & execute" permissions (if they have more, that's fine).
You can try editing the permissions (like giving additional permissions to the "users" group).
Also, please try temporarily disabling your anti-virus and/or firewall to see if this changes the behaviour.

If it does, please add AnyLexic to the exception list in your AV/firewall.