ERROR(ORPSIM-16492)

I am new to PSPICE as well as the community and i'm trying some circuits given by my professor for an assignment. I've completed most of them which helped me in understanding how the software works but i'm stuck at this part and i can't find out what's wrong. The message i get when trying running the simulation is:

   *Analysis directives:
.TRAN  0 2ms 0
.STEP LIN PARAM VOLTAGE 0.5 0.6 0.01
.PROBE64 V(alias(*)) I(alias(*)) W(alias(*)) D(alias(*)) NOISE(alias(*))
.INC "..\SCHEMATIC1.net"

**** INCLUDING SCHEMATIC1.net ****
* source EXERCISE 3
V_Vin         N00126 0  AC <AC>
----------------------------\$
ERROR(ORPSIM-16492): Missing value
+SIN 0 {VOLTAGE} 1k 0 0 0
C_C1         N00126 N00167  10u  TC=0,0
J_J1         N00364 N00167 N00198 Jbreakn
R_RS         0 N00198  220 TC=0,0
C_Cs         0 N00198  100u  TC=0,0
R_RD         N00364 N00399  2.2k TC=0,0
V_V1         N00399 0 0Vdc
C_C2         N00364 N00530  10u  TC=0,0
R_RL         0 N00530  4.7k TC=0,0
R_RG         0 N00167  1meg TC=0,0
.PARAM  voltage=1

**** RESUMING initial.cir ****
.END


The simulation is a parametric analysis with the VAMPL of the AC source as a global parameter and the circuit is this:

The JBreakN is modified with the parameters:

.model Jbreakn NJF (Beta=550u Rs=1 Rd=1 Betatce=-.5 Lambda=10m Vto=-3.44


+ Vtotc=0 Cgd=5p M=.3333 Pb=1 Fc=.5 Cgs=5p Isr=1p Nr=2 Is=100f + N=1 Xti=3 Alpha=10u Vk=100 Kf=1E-18 Af=1)

I am sorry if the post is too long i am trying to give as much information as i can. Thanks in advance to anyone answering.

So its actually a little quirky. When you first add the source to the schematic, and don't alter the AC parameter, it is assigned a default value (0) and it will simulate fine. But if you open the property, and even though you don't write anything in the field, and click OK, it will assign <AC> as the value to the parameter. It will therefore give an error next time you run the simulator, as <AC> is not a valid value..