Here's a smaller and better readable version of the call stack

Call Stack Information:
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|Address |Module |Unit |Class
|Procedure/Method |Line |
--------------------------------------------------------------------------------------------------------------------
| Exception Thread: ID=2464; Priority=0; Class=; [Main]
|
|------------------------------------------------------------------------------------------------------------------|
|IB_Session.pas |TIB_SessionBase |HandleException

|IB_Session.pas |TIB_SessionBase |HandleException
|IB_Components.pas |TIB_Connection
|AllocateStmtHandle
|IB_Components.pas |TIB_Connection |AllocateStmtHandle

|IB_Components.pas |TIB_Statement |SysAllocate

|IB_Components.pas |TIB_Statement |SysPrepare

|IB_Components.pas |TIB_Statement |SysPrepare

|IB_Components.pas |TIB_Dataset |SysPrepare

|IB_Components.pas |TIB_Statement |Prepare

|IB_Components.pas |TIB_Statement |Prepare

|IB_Schema.pas | |SchemaComputedCols

|IB_Schema.pas | |SchemaComputedCols

|IB_Components.pas |TIB_SchemaCache |GetSchemaCacheList

|IB_Components.pas |TIB_SchemaCache |GetSchemaCacheList

|IB_Components.pas |TIB_Statement |GetColumnIsReadOnly

|IB_Components.pas |TIB_Statement |GetColumnIsReadOnly

|IB_Components.pas |TIB_Dataset |GetColumnIsReadOnly

|IB_Components.pas |TIB_Dataset |GetControlIsReadOnly

|IB_FieldDataLink.pas|TIB_FieldDataLink |GetReadOnly

|IBC_CustomEdit.IMP |TIB_CustomEdit |EditingChanged

|IB_Controls.pas |TIB_CustomEdit |SysStateChanged

|IB_Control.IMP |TIB_CustomEdit |StateChanged

|IB_Components.pas |TIB_Dataset |DoLinkStateChanged

|IB_Components.pas |TIB_Dataset |DoLinkStateChanged

|IB_Components.pas |TIB_Dataset |SysStateChanged

|IB_Components.pas |TIB_Dataset |SysStateChanged
|IB_Components.pas |TIB_Dataset
|StateChanged
|IB_Components.pas |TIB_Dataset |StateChanged

|IB_Components.pas |TIB_Dataset |SetState

|IB_Components.pas |TIB_Dataset |SetState

|IB_Components.pas |TIB_Dataset |SysUpdateState

|IB_Components.pas |TIB_Dataset |SysUpdateState

|IB_Components.pas |TIB_Dataset |SysActiveChange
|IB_Components.pas |TIB_Statement |SysClose
|IB_Components.pas |TIB_Statement
|SysClose
|IB_Components.pas |TIB_Dataset |SysClose

|IB_Components.pas |TIB_BDataset |GotoBOF

|IB_Components.pas |TIB_BDataset |GotoBOF

|IB_Components.pas |TIB_Dataset |SysKeyDataChange
|IB_Components.pas |TIB_Dataset
|SysKeyDataChange
|IB_Components.pas |TIB_Dataset |IB_KeyDataChange

|IB_Components.pas |TIB_Statement |ProcessLinkEvent

|IB_Components.pas |TIB_Statement |ProcessLinkEvent
|IB_Components.pas |TIB_Dataset
|ProcessLinkEvent
|IB_Components.pas |TIB_Statement |SysAfterFieldDataChange

|IB_Components.pas |TIB_Statement |SysAfterFieldDataChange

|IB_Components.pas |TIB_BDataset |SysAfterFieldDataChange
|IB_Components.pas |TIB_Dataset
|SysActiveChange
|IB_Components.pas |TIB_Statement |SysClose

|IB_Components.pas |TIB_Statement |SysClose

|IB_Components.pas |TIB_Dataset |SysClose

|IB_Components.pas |TIB_Dataset |Close

|IB_Components.pas |TIB_Dataset |Close

|Main.pas |TMainForm |ToolButton4Click

|------------------------------------------------------------------------------------------------------------------|