Sitecore - Upload File Error in Media Library - sitecore

Question

When I click on the "Upload File" button in the Sitecore Media Library, an Exception is thrown. The "Upload Files (Adavanced)" button works fine.
This is the error message:
Server Error in '/' Application.
Value cannot be null.
Parameter name: value
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.ArgumentNullException: Value cannot be null.
Parameter name: value
Source Error:
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
Stack Trace:
[ArgumentNullException: Value cannot be null.
Parameter name: value]
Sitecore.Text.UrlString.Add(String key, String value) +149
Sitecore.Shell.Framework.Commands.Media.Upload.Run(ClientPipelineArgs args) +1801
Sitecore.Intranet.Commands.Media.Upload.RunOverridden(ClientPipelineArgs args) +421
[TargetInvocationException: Exception has been thrown by the target of an invocation.]
System.RuntimeMethodHandle._InvokeMethodFast(Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner) +0
System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks) +1255
System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) +38
Sitecore.Pipelines.Processor.Invoke(PipelineArgs args) +318
Sitecore.Nexus.Pipelines.NexusPipelineApi.Resume(PipelineArgs args, Pipeline pipeline) +330
Sitecore.Pipelines.Pipeline.DoStart(PipelineArgs args) +208
Sitecore.Pipelines.Pipeline.Start(PipelineArgs args, Boolean atomic) +182
Sitecore.Web.UI.Sheer.ClientPage.RunPipelines() +280
Sitecore.Web.UI.Sheer.ClientPage.OnPreRender(EventArgs e) +530
Sitecore.Shell.Applications.ContentManager.ContentEditorPage.OnPreRender(EventArgs e) +25
System.Web.UI.Control.PreRenderRecursiveInternal() +108
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3394
Any idea how I can fix this? Alternativly I would like to hide the "Upload File" button. How can I do that?
Thanks :)

Answer 1

The button was not working with you only in firefox.
You can hide it by going to the core database, and remove this item
/sitecore/content/Applications/Content Editor/Editors/Media/Media Folder/Buttons/Upload - Multi
I tested it, and it works.