I've been using RD Tabs on Windows 10 x64 Enterprise tech preview for a while now. Today, it didn't start the first time I tried to open it, giing the error messages below. It asked me to forward these to the forum, so here is the data (although it would have been really nice if I could have copied and pasted the information, instead of having to take a screenshot and trying four online OCR sites before I found one that worked ):

0 RD Tabs encountered an unexpected error while attempting to generate or send an error reportlf you could report this occurance (and the below exception) to the author through
the Avian Waves forums, that would help tremendously! I apologize for this problem. Thank you.

System.InvalidOperationException: An error occurred creating the form. See Exception.InnerException for details. The error is: -- Execution Breadcrumb (See Inner Exception for
original error)--
RDTabsMain.New: METHOD ENTERED.
RDTabsMain.New: Main form reference set.
RDTabsMain.New: Exception raised while generating or reading the Error Report GUID.
---> System.Exception: -- Execution Breadcrumb (See Inner Exception for original error) --
RDTabsMain.New: METHOD ENTERED.
RDTabsMain.New: Main form reference set.
RDTabsMain.New: Exception raised while generating or reading the Error Report GUID.
---> System.Configuration.ConfigurationErrorsException: Configuration system failed to initialize ---> System.Configuration.ConfigurationErrorsException: '.', hexadecimal value
Ox00, is an invalid character. Line 16, position 1. (C:\ Users \jack.turner\AppData \ Local \AvianWaves\ RDTabs.eceUrlmclvpzvfnlz5wuk2cjrmciedokdxu3eu \ 2.1.25.0\ user.config line
16) ---> System.Xml.XmlException: '.', hexadecimal value Ox00, is an invalid character. Line 16, position 1.
at System.Xml.XmlTectReaderImpl.Throw(Exception e)
at System.Xml.XmlTectReaderImpl.ThrowInvalidChar(Int32 pos, Char invChar)
at System.Xml.XmlTectReaderImpl.ParseTect(Int32& startPos, Int32& endPos, Int32& outOrChars)
at System.Xml.XmlTectReaderImpl.ParseTectO
at System.Xml.XmlTectReaderImpl.ParseElementContentO
at System.Xml.XmlTextReaderlmpl.SkipO
at System.Configuration.XmlUtil.StrictSkipToNextElement(ExceptionAction action)
at System.Configuration.BaseConfigurationRecord.ScanSectionsRecursive(XmlUtil xmlUtil, String parentConfigKey, Boolean inLocation, String locationSubPath,
OverrideModeSetting overrideMode, Boolean skipinChildApps)
at System.Configuration.BaseConfigurationRecord.ScanSectionsRecursive(XmlUtil xmlUtil, String parentConfigKey, Boolean inLocation, String locationSubPath,
OverrideModeSetting overrideMode, Boolean skipinChildApps)
at System.Configuration.BaseConfigurationRecord.ScanSections(XmlUtil xmlUtil)
at System.Configuration.BaseConfigurationRecord.lnitConfigFromFile0
--- End of inner exception stack trace ---
at System.Configuration.ConfigurationSchemaErrors.ThrowlfErrors(Boolean ignoreLocal)
at System.Configuration.BaseConfigurationRecord.ThrowlfInitErrors0
at System.Configuration.ClientConfigurationSystem.OnConfigRemoved(Object sender, InternalConfigEventArgs e)
--- End of inner exception stack trace ---
at System.Configuration.ConfigurationManager.RefreshSection(String sectionName)
at System.Configuration.ClientSettingsStore.ReadSettings(String sectionName, Boolean isUserScoped)
at System.ConfigurationlocalFileSettingsProvider.GetPropertyValues(SettingsContect context, SettingsPropertyCollection properties)
at System.Configuration.SettingsBase.GetPropertiesFromProvider(SettingsProvider provider)
at System.Configuration.SettingsBase.GetPropertyValueByName(String propertyName)
at System.Configuration.SettingsBase.get_ltem(String propertyName)
at System.Configuration.ApplicationSettingsBase.GetPropertyValue(String propertyName)
at System.Configuration.ApplicationSettingsBase.get_ltem(String propertyName)
at RDTabs.My.MySettings.get_ErrorReportURLO
at RDTabs.My.MyApplication.MyApplication_UnhandledException(Object sender, UnhandledExceptionEventArgs e)
--- End of inner exception stack trace ---
at RDTabs.RDTabsMain..ctor0
--- End of inner exception stack trace ---
at RDTabs.My.MyProject.MyForms.Create_Instance JTHT Instance)
at RDTabs.My.MyApplication.OnCreateMainFormO
at Microsoft.VisualBasic.ApplicationSentices.WindowsFormsApplicationBase.0nRun0
at MicrosoftVisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModelO

It looks like the user.config file is corrupted based on...

Configuration system failed to initialize ---> System.Configuration.ConfigurationErrorsException: '.', hexadecimal value
Ox00, is an invalid character. Line 16, position 1. (C:\ Users \jack.turner\AppData \ Local \AvianWaves\ RDTabs.eceUrlmclvpzvfnlz5wuk2cjrmciedokdxu3eu \ 2.1.25.0\ user.config line
16) ---> System.Xml.XmlException: '.', hexadecimal value Ox00, is an invalid character. Line 16, position 1.

You can try hand editing the user.config or just delete it and it will recreate, but you will lose your settings.