An error occurred in the ‘Sample File....

Hi all,

I am struggling with a problem in the Power Query. I have a dataset connected to some shared teams folders, but it gives some errors. 

 some of my tables load without problems and some give an error. When I refresh the Sample File and Transform Sample File, this seems to be solved. But, in one step in my data transformation i get an error in all my tables in while it's executing the step "invoke custom function1". 2 steps further ("Removed other columns1") this error suddenly disapears.

Another error message that i get is the following: 

An error occurred in the ‘Sample File (12)’ query. DataSource.Error: SharePoint: Request failed: https://provincie.sharepoint.com/sites/prjct-WerkgroepManagementcyclus/Gedeelde documenten/General/Inleveren data/10.1_DMG3_2021_xlsm/_api/contextinfo
Details:
    DataSourceKind=SharePoint
    DataSourcePath=https://provincie.sharepoint.com/sites/prjct-WerkgroepManagementcyclus
    SPRequestGuid=6a65f99f-3041-c000-8bc1-a8e21197d87c

 This error keeps coming back, and disolves when i refresh the sample file and transform sample file. 

Does anyone has an idea why this is happening? Below I added the code for more detailed info about the steps

let
    Source = SharePoint.Files("https://provincie.sharepoint.com/sites/prjct-WerkgroepManagementcyclus/", [ApiVersion = 15]),
    #"Filtered Hidden Files1" = Table.SelectRows(Source, each [Attributes]?[Hidden]? <> true),
    #"Filtered Rows3" = Table.SelectRows(#"Filtered Hidden Files1", each Text.Contains([Folder Path], "Inleveren VGR")),
    #"Invoke Custom Function1" = Table.AddColumn(#"Filtered Rows3", "Transform File (6)", each #"Transform File (6)"([Content])),
    #"Renamed Columns1" = Table.RenameColumns(#"Invoke Custom Function1", {"Name", "Source.Name"}),
    #"Removed Other Columns1" = Table.SelectColumns(#"Renamed Columns1", {"Source.Name", "Transform File (6)"}),
    #"Expanded Table Column1" = Table.ExpandTableColumn(#"Removed Other Columns1", "Transform File (6)", Table.ColumnNames(#"Transform File (6)"(#"Sample File (6)"))),
    #"Changed Type" = Table.TransformColumnTypes(#"Expanded Table Column1",{{"Source.Name", type text}, {"Asset", type text}, {"TotaalKrediet", Int64.Type}, {"WerkelijktotVorigJaar", Int64.Type}, {"jaar(t)Prog", Int64.Type}, {"jaar(t+1)Prog", Int64.Type}, {"jaar(t+2)Prog", Int64.Type}, {"jaar(t+3) Prog", Int64.Type}, {"jaar(t+4)Prog", Int64.Type}}),
    #"Filtered Rows" = Table.SelectRows(#"Changed Type", each ([Asset] <> null and [Asset] <> "Let op fout in tabel Youssri (MIP Begroot) mist totaalkrediet" and [Asset] <> "Let op fout in tabel Youssri (MIP Begroot) mist werkelijk tot vorigjaar")),
    #"Merged Queries" = Table.NestedJoin(#"Filtered Rows", {"Source.Name"}, VGR, {"Source.Name"}, "VGR", JoinKind.LeftOuter),
    #"Expanded VGR" = Table.ExpandTableColumn(#"Merged Queries", "VGR", {"Index"}, {"VGR.Index"}),
    #"Filtered Rows2" = Table.SelectRows(#"Expanded VGR", each ([Asset] <> "0")),
    #"Changed Type1" = Table.TransformColumnTypes(#"Filtered Rows2",{{"TotaalKrediet", Currency.Type}, {"WerkelijktotVorigJaar", Currency.Type}, {"jaar(t)Prog", Currency.Type}, {"jaar(t+1)Prog", Currency.Type}, {"jaar(t+2)Prog", Currency.Type}, {"jaar(t+3) Prog", Currency.Type}, {"jaar(t+4)Prog", Currency.Type}}),
    #"Unpivoted Columns" = Table.UnpivotOtherColumns(#"Changed Type1", {"Source.Name", "Asset", "TotaalKrediet", "VGR.Index"}, "Jaar-t", "Bedrag Prognose"),
    #"Replaced Value" = Table.ReplaceValue(#"Unpivoted Columns","Prog","",Replacer.ReplaceText,{"Jaar-t"}),
    #"Changed Type2" = Table.TransformColumnTypes(#"Replaced Value",{{"TotaalKrediet", Int64.Type}, {"Bedrag Prognose", Int64.Type}}),
    #"Added Custom" = Table.AddColumn(#"Changed Type2", "Index + Asset", each [VGR.Index] & "-" & [Asset]),
    #"Changed Type3" = Table.TransformColumnTypes(#"Added Custom",{{"Index + Asset", type text}})
in
    #"Changed Type3"

Thanks`!