There are some typing mistakes in ur10_forward_kinematic(). For example in the input list the variable name is Theta2, whereas in the code you are using Theta_2. You need to use the same name in both places. Also on line 39, you are using p06 whereas the actual name is P06 remember the variable names are case sensitive.
The file ur10_inverse_kinematic() contains some more involved problems. For example, at the beginning of your code you are using Theta1, Theta2, ... Theta6 but their values are not defined. You are not giving their values as function input neither defining inside the function. MATLAB has no way of knowing what values to take when the function run.