Trying to troubleshoot where the problem lies on my VFD and spindle.

I am running into repeated overcurrent errors as I attempt to run my CNC file. I am getting E.Oc.A, E.Oc.N, E.Oc.S, and E.Oc.D errors. The time from starting to error is variable. Yesterday after a long run I got a single overheating error which has not occurred since though it leads me to believe something happened at that time to cause my current error. I have reviewed my various settings in the vfd which have not changed. I monitored the amps during the run to see if there would be a change in current draw when it received the error but there is no change there either.

I could use some advice as to what to look into next to determine the issue. Is this a VFD problem that requires replacement or is this a spindle issue? How can I best determine this?