I have the same error as in this post deploy says macroalias is missing but it isn't

I have the exact same error, but can't clone dev to local as in the above post, as this is a migration of an existing site from 6 to 7.15.5 (via CMSImport) then to the Umbraco cloud.

I am stumped as to how I am going to migrate this site, does anyone have any ideas, please?

In my case the error message is title casing the camel cased property name from documentRoot to documentroot, which suggests there is something going awry in the regex, or maybe before that in the ValueConnectors.RichtextValueConnector.GetValue:

-- EXCEPTION ---------------------------------------------------
 (proper exception traces at the end of this log)
System.Collections.Generic.KeyNotFoundException: Parameter not found: documentroot, on macro: xxxxDocumentList.
----------------------------------------------------------------

EXCEPTION:

System.Collections.Generic.KeyNotFoundException: Parameter not found: documentroot, on macro: SeftonDocumentList.
   at Umbraco.Deploy.Core.MacroParser.<>c__DisplayClass8_1.<ProcessValue>b__1(Match attributeMatch)
   at System.Text.RegularExpressions.RegexReplacement.Replace(MatchEvaluator evaluator, Regex regex, String input, Int32 count, Int32 startat)
   at System.Text.RegularExpressions.Regex.Replace(String input, MatchEvaluator evaluator)
   at Umbraco.Deploy.Core.MacroParser.<>c__DisplayClass8_0.<ProcessValue>b__0(Match macroMatch)
   at System.Text.RegularExpressions.RegexReplacement.Replace(MatchEvaluator evaluator, Regex regex, String input, Int32 count, Int32 startat)
   at System.Text.RegularExpressions.Regex.Replace(String input, MatchEvaluator evaluator)
   at Umbraco.Deploy.Core.MacroParser.ProcessValue(String value, ICollection`1 dependencies, Direction direction)
   at Umbraco.Deploy.ValueConnectors.RichtextValueConnector.GetValue(Property property, ICollection`1 dependencies)
   at System.Linq.Enumerable.ToDictionary[TSource,TKey,TElement](IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector, IEqualityComparer`1 comparer)