I have had the same problem...sort of. I can install the module and get it working and then after a day or two without a post or any changes it give the error 'module not available'. I then re-install the module and it works again... This has happened 3 times now on  4.3.3.

Here is what is in the log files. Not much help but here it is.

Message: DotNetNuke.Services.Exceptions.ModuleLoadException: External component has thrown an exception. ---> System.Web.HttpCompileException: External component has thrown an exception. at System.Web.Compilation.AssemblyBuilder.Compile() at System.Web.Compilation.BuildProvidersCompiler.PerformBuild() at System.Web.Compilation.BuildManager.CompileWebFile(VirtualPath virtualPath) at System.Web.Compilation.BuildManager.GetVPathBuildResultInternal(VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile) at System.Web.Compilation.BuildManager.GetVPathBuildResultWithNoAssert(HttpContext context, VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile) at System.Web.UI.TemplateControl.LoadControl(VirtualPath virtualPath) at DotNetNuke.UI.Skins.Skin.InjectModule(Control objPane, ModuleInfo objModule, PortalSettings PortalSettings) --- End of inner exception stack trace ---

Scott,

I only have it on the module on one page with nothing else on it. It worked fine in earlier 4x versions. I just started happening. I will try to figure out if I am doing anything to cause it on my server. 

"Is it a specific screen or the whole module"

This error occurs as soon as the Tab is clicked so the whole module would be my best answer.