I'm getting "UNKNOWN - The WMI query had problems. The error text from wmic is:"

This is a generic error message for problems encountered with the wmic command.

The plugin adds some English text to common/known wmic problems but if wmic throws some other error then the plugin can't do anything about it and you will need to troubleshoot the wmic command yourself and ideally report the solution to us so that we can add some useful error message to the plugin.

Use the -d parameter to see the wmic command used and then test directly with the wmic command.
Normally, you'd try different hosts, usernames, passwords, operating system versions etc to try and find the common denominator to help you troubleshoot.

As an example, if wmic returns:
[librpc/rpc/dcerpc_connect.c:329:dcerpc_pipe_connect_ncacn_ip_tcp_recv()] failed NT status (c00000b5) in dcerpc_pipe_connect_ncacn_ip_tcp_recv
[librpc/rpc/dcerpc_connect.c:790:dcerpc_pipe_connect_b_recv()] failed NT status (c00000b5) in dcerpc_pipe_connect_b_recv
[wmi/wmic.c:196:main()] ERROR: Login to remote object.
NTSTATUS: NT_STATUS_IO_TIMEOUT - NT_STATUS_IO_TIMEOUT

We know that this relates to a hostname that probably does not resolve via DNS.

But if we get an error like:
[librpc/rpc/dcerpc_connect.c:329:dcerpc_pipe_connect_ncacn_ip_tcp_recv()]
failed NT status (c00000c4) in dcerpc_pipe_connect_ncacn_ip_tcp_recv
[librpc/rpc/dcerpc_connect.c:790:dcerpc_pipe_connect_b_recv()] failed NT
status (c00000c4) in dcerpc_pipe_connect_b_recv

We have no idea what this error really means and what causes it.