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Error Description
We are aware of an error generated on connection of SWQL Studio 3.0.0.336 (and possibly prior versions) to Orion Platform 2020.2.6 HF2 which returns the following error message:

Please note that you can click Continue above and run queries in the Query Tabs, but the tree navigation is not rendering.
It's being tracked as a GitHub issue and is set for release after unit tests and the build system rolls a new version. I will update this post (with a link to the new MSI) when it's been remedied.
Example Error Text
See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.
************** Exception Text **************
System.FormatException: Input string was not in a correct format.
at System.Text.StringBuilder.FormatError()
at System.Text.StringBuilder.AppendFormatHelper(IFormatProvider provider, String format, ParamsArray args)
at System.Text.StringBuilder.AppendFormat(String format, Object[] args)
at SwqlStudio.DocumentationBuilder.ToToolTip(ITypedMetadata metadata, IObsoleteMetadata obsoleteMetadata)
at SwqlStudio.TreeNodesBuilder.AddPropertiesToNode(IMetadataProvider provider, TreeNode entityNode, IEnumerable`1 properties)
at SwqlStudio.TreeNodesBuilder.MakeEntityTreeNode(IMetadataProvider provider, Entity entity)
at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
at System.Linq.Buffer`1..ctor(IEnumerable`1 source)
at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)
at SwqlStudio.TreeNodesBuilder.RebuildDatabaseNode(TreeNode databaseNode, IMetadataProvider provider)
at SwqlStudio.ObjectExplorer.ObjectExplorer.<>c__DisplayClass43_0.b__1()
************** Loaded Assemblies **************
mscorlib
Assembly Version: 4.0.0.0
Win32 Version: 4.8.4430.0 built by: NET48REL1LAST_B
CodeBase: file:///C:/Windows/Microsoft.NET/Framework64/v4.0.30319/mscorlib.dll
----------------------------------------
SwqlStudio
Assembly Version: 3.0.0.336
Win32 Version: 3.0.0.336
CodeBase: file:///C:/Program%20Files%20(x86)/SolarWinds/Orion%20SDK/SWQL%20Studio/SwqlStudio.exe
----------------------------------------
SolarWinds.Logging
Assembly Version: 3.0.0.336
Win32 Version: 3.0.0.336
CodeBase: file:///C:/Program%20Files%20(x86)/SolarWinds/Orion%20SDK/SWQL%20Studio/SolarWinds.Logging.DLL
----------------------------------------
System
Assembly Version: 4.0.0.0
Win32 Version: 4.8.4380.0 built by: NET48REL1LAST_B
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System/v4.0_4.0.0.0__b77a5c561934e089/System.dll
----------------------------------------
System.Windows.Forms
Assembly Version: 4.0.0.0
Win32 Version: 4.8.4410.0 built by: NET48REL1LAST_B
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Windows.Forms/v4.0_4.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
----------------------------------------
System.Drawing
Assembly Version: 4.0.0.0
Win32 Version: 4.8.4395.0 built by: NET48REL1LAST_B
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Drawing/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
----------------------------------------
System.Core
Assembly Version: 4.0.0.0
Win32 Version: 4.8.4395.0 built by: NET48REL1LAST_B
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Core/v4.0_4.0.0.0__b77a5c561934e089/System.Core.dll
----------------------------------------
log4net
Assembly Version: 2.0.12.0
Win32 Version: 2.0.12.0
CodeBase: file:///C:/Program%20Files%20(x86)/SolarWinds/Orion%20SDK/SWQL%20Studio/log4net.DLL
----------------------------------------
System.Configuration
Assembly Version: 4.0.0.0
Win32 Version: 4.8.4190.0 built by: NET48REL1LAST_B
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Configuration/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll
----------------------------------------
System.Xml
Assembly Version: 4.0.0.0
Win32 Version: 4.8.3761.0 built by: NET48REL1
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Xml/v4.0_4.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------
SolarWinds.SDK.Swis.Contract
Assembly Version: 3.0.0.336
Win32 Version: 3.0.0.336
CodeBase: file:///C:/Program%20Files%20(x86)/SolarWinds/Orion%20SDK/SWQL%20Studio/SolarWinds.SDK.Swis.Contract.DLL
----------------------------------------
System.ServiceModel
Assembly Version: 4.0.0.0
Win32 Version: 4.8.4261.0 built by: NET48REL1LAST_B
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.ServiceModel/v4.0_4.0.0.0__b77a5c561934e089/System.ServiceModel.dll
----------------------------------------
WeifenLuo.WinFormsUI.Docking
Assembly Version: 3.0.6.0
Win32 Version: 3.0.6.0
CodeBase: file:///C:/Program%20Files%20(x86)/SolarWinds/Orion%20SDK/SWQL%20Studio/WeifenLuo.WinFormsUI.Docking.DLL
----------------------------------------
netstandard
Assembly Version: 2.0.0.0
Win32 Version: 4.8.3761.0
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/netstandard/v4.0_2.0.0.0__cc7b13ffcd2ddd51/netstandard.dll
----------------------------------------
ScintillaNET
Assembly Version: 3.6.3.0
Win32 Version: 3.6.3.0
CodeBase: file:///C:/Program%20Files%20(x86)/SolarWinds/Orion%20SDK/SWQL%20Studio/ScintillaNET.DLL
----------------------------------------
WeifenLuo.WinFormsUI.Docking.ThemeVS2015
Assembly Version: 3.0.6.0
Win32 Version: 3.0.6.0
CodeBase: file:///C:/Program%20Files%20(x86)/SolarWinds/Orion%20SDK/SWQL%20Studio/WeifenLuo.WinFormsUI.Docking.ThemeVS2015.DLL
----------------------------------------
System.Xml.Linq
Assembly Version: 4.0.0.0
Win32 Version: 4.8.3761.0 built by: NET48REL1
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Xml.Linq/v4.0_4.0.0.0__b77a5c561934e089/System.Xml.Linq.dll
----------------------------------------
System.Data
Assembly Version: 4.0.0.0
Win32 Version: 4.8.4290.0 built by: NET48REL1LAST_B
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_64/System.Data/v4.0_4.0.0.0__b77a5c561934e089/System.Data.dll
----------------------------------------
System.ServiceModel.Primitives
Assembly Version: 4.7.0.0
Win32 Version: 4.700.19.56502
CodeBase: file:///C:/Program%20Files%20(x86)/SolarWinds/Orion%20SDK/SWQL%20Studio/System.ServiceModel.Primitives.DLL
----------------------------------------
SMDiagnostics
Assembly Version: 4.0.0.0
Win32 Version: 4.8.4261.0 built by: NET48REL1LAST_B
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/SMDiagnostics/v4.0_4.0.0.0__b77a5c561934e089/SMDiagnostics.dll
----------------------------------------
Accessibility
Assembly Version: 4.0.0.0
Win32 Version: 4.8.3761.0 built by: NET48REL1
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/Accessibility/v4.0_4.0.0.0__b03f5f7f11d50a3a/Accessibility.dll
----------------------------------------
System.IdentityModel
Assembly Version: 4.0.0.0
Win32 Version: 4.8.4261.0 built by: NET48REL1LAST_B
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.IdentityModel/v4.0_4.0.0.0__b77a5c561934e089/System.IdentityModel.dll
----------------------------------------
System.Runtime.Serialization
Assembly Version: 4.0.0.0
Win32 Version: 4.8.4261.0 built by: NET48REL1LAST_B
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Runtime.Serialization/v4.0_4.0.0.0__b77a5c561934e089/System.Runtime.Serialization.dll
----------------------------------------
System.ServiceModel.Internals
Assembly Version: 4.0.0.0
Win32 Version: 4.8.4261.0 built by: NET48REL1LAST_B
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.ServiceModel.Internals/v4.0_4.0.0.0__31bf3856ad364e35/System.ServiceModel.Internals.dll
----------------------------------------
System.ServiceModel.Channels
Assembly Version: 4.0.0.0
Win32 Version: 4.8.4261.0 built by: NET48REL1LAST_B
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.ServiceModel.Channels/v4.0_4.0.0.0__31bf3856ad364e35/System.ServiceModel.Channels.dll
----------------------------------------
System.ServiceModel.Web
Assembly Version: 4.0.0.0
Win32 Version: 4.8.4261.0 built by: NET48REL1LAST_B
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.ServiceModel.Web/v4.0_4.0.0.0__31bf3856ad364e35/System.ServiceModel.Web.dll
----------------------------------------
System.ServiceModel.Security
Assembly Version: 4.7.0.0
Win32 Version: 4.700.19.56502
CodeBase: file:///C:/Program%20Files%20(x86)/SolarWinds/Orion%20SDK/SWQL%20Studio/System.ServiceModel.Security.DLL
----------------------------------------
System.ServiceModel.NetTcp
Assembly Version: 4.7.0.0
Win32 Version: 4.700.19.56502
CodeBase: file:///C:/Program%20Files%20(x86)/SolarWinds/Orion%20SDK/SWQL%20Studio/System.ServiceModel.NetTcp.DLL
----------------------------------------
Microsoft.GeneratedCode
Assembly Version: 1.0.0.0
Win32 Version: 4.8.3761.0 built by: NET48REL1
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Xml/v4.0_4.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------
System.Numerics
Assembly Version: 4.0.0.0
Win32 Version: 4.8.3761.0 built by: NET48REL1
CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Numerics/v4.0_4.0.0.0__b77a5c561934e089/System.Numerics.dll
----------------------------------------
************** JIT Debugging **************
To enable just-in-time (JIT) debugging, the .config file for this
application or computer (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.
For example:
When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the computer
rather than be handled by this dialog box.
Resolution
Upgrade SWQL Studio to 3.1.0.343 (or later).
