Hello all, I've scoured the internet but I can't find any information on this error.

What I'm trying to do is import some devices from a scheduled scan but it continually fails.
For context we have probably 300 devices in our Solarwinds setup and apart from that it runs amazingly well but I can't figure this issue out and therefore cannot import any new equipment.
This is the uppermost part of the error log.
Message: count is less than zero
ErrorSite: SolarWinds.Orion.Core.Models.V1.ElementLicenseInfo..ctor
ErrorType: System.ArgumentException
Stack:
at SolarWinds.Orion.Core.Models.Discovery.ElementLicenseInfo..ctor(String name, Int32 managedCount, Int32 countAfterImport, Int32 maxCount)
at Orion_Discovery_Results_Preview.<>c__DisplayClass34_0.<ValidateUserInput>b__2(IGrouping`2 typeGroup)
at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
at Orion_Discovery_Results_Preview.ValidateUserInput()
at SolarWinds.Orion.Core.Web.Discovery.WizardBasePage.imgbNext_Click(Object sender, EventArgs e)
at System.Web.UI.WebControls.LinkButton.OnClick(EventArgs e)
at System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String eventArgument)
at System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)
at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
If anyone has any ideas I'd be really grateful to hear them.
Cheers.