vmx(4) interfaces do not have ALTQ support on pfSense 2.5, they had ALTQ support on 2.4
Shamelessly copied from #7066 since it's the same issue here.
Attempting to configure traffic shaping on a pfSense 2.5 VMware VM with vmx NICs results in an error:
There were error(s) loading the rules: pfctl: vmx0: driver does not support altq - The line in question reads :
The same configuration worked on pfSense 2.4.
If ALTQ support is removed from vmx and not coming back, we will need to remove vmx from the list of ALTQ-capable NICs and disable the shaper on upgrade if it is in use.