How to stop infinite loop in VBA Excel in Heat pump simulation?

Dear all,

Currently, I do vapor compression heat pump cycle simulation in Visual Basic for Application. The thermo-physical properties of fluids are taken from Refprop. The program keep on looping in outlet condenser side. Especially on "DoEvent" script. In the iteration, I see the iteration value of parameters has some correct value. So I try to stop the loop on that value by changing "DoEvent" to "Exit Do" script but the Excel is not responding.

I am sorry I do not post the code. Actually, the script is too long and I am confused which part I can share.

Do you have any solution?

Thank you for your help

Dear Keebellah

Thank you for your help. I will try your suggestion. I will ask if i find problems.

Thank you so much

Teguh