OLE DB or ODBC Error: We cannot convert the value null to type Logical - powerbi

Question

I am calculating following calculated column in query editor:
End Date =
if [Date_1] <> null
then [Date_1]
else if [Date_2]<>null
then [Date_2]
else DateTime.Date(DateTime.LocalNow())
Based on this column, the following table is calculated:
Resident Payer Dates =
SELECTCOLUMNS (
GENERATE (
'Table1',
FILTER (
ALLNOBLANKROW ( Dates[Date] ),
Dates[Date] >= 'Table1'[Start Date]
&& Dates[Date] <= 'Table1'[End Date]
)
),
"Id", 'Table1'[Id],
"Date", Dates[Date]
)
Everything is working fine till here.
However, for some reason, I need to change the End Date column with the following formula:
End Date =
if [Date_1] <> null
then Date.AddDays([Date_1], -1)
else if [Date_2]<>null
then Date.AddDays([Date_2],-1)
else DateTime.Date(DateTime.LocalNow())
However, when I try to apply the changes, I am getting the following error:
I am totally clueless about why we are running in this error with a simple change like above, as the change is not producing any null values.
Any help and guidance would be appreciated.

Answer 1

For anyone who faces such issue in future:
Here, the query editor shows no errors and the evaluation is completed till the last step successfully. However, when you try to apply the changes, the error mentioned above is encountered.
With a lot of searches, I figured out that the column got corrupted, for reasons being still unknown.
To solve this, all you have to do is to remove the step/column completely and recreate it, the error will go away.