What do you know? I diceded to wait for a while if someone knew cure for my problem... came back to my site and - the form was OK! This REALLY is strange.
The Formaster IS the only controll on that page
This message I got when tried to click the "Manage form":
Error: Module is currently unavailable.
DotNetNuke.Services.Exceptions.ModuleLoadException: Object reference not set to an instance of an object. --->
System.NullReferenceException: Object reference not set to an instance of an object. at
DotNetNuke.Modules.Admin.Modules.ModuleSettingsPage.cmdUpdate_Click(Object Sender, EventArgs e)
--- End of inner exception stack trace ---
But anyway - All is fine now 