It's been a while since I've dealt with things like this but I'm guessing that you need to remove the menu_destroy(menuid) in Destroy_Menu(). IIRC, the menu handler function still gets called when the menu goes away so if you destroy it in Destroy_Menu() then the menu id will not exist when OpenMenu_sub() gets called automatically.
P.S. The error references line 134 but line 134 of what you posted is not a line that can cause an error (I can find the line but it bring into doubt that that is the actual code that is running). When posting errors and code, I recommend that you post the exact code that was used to compile that plugin. Also, when posting the full plugin, it's probably easier and more reliable to attach the .sma file.