Excel crashing randomly when running macro - excel

Question

I'm having an issue with the following code, that is supposed to sequentially open 〜100 csv files, check for a value in a cell (validation, if it is file with correct structure), copy single line of data and paste it into ThisWorkbook.Worksheets("2 CSV").Range("B" & row_number).
This solution worked for two years until this month. Now the whole Excel crashes randomly on any file without any error message. Sometimes it manages to loop through 20 files, sometimes 5.
The weirdest thing is, that I can loop manually using F8 through the whole thing without any problem.
The macro:
Sub b_load_csv()
Dim appStatus As Variant
Dim folder_path As String 'folder path to where CSVs are stored
Dim file_name As String 'file name of current CSV file
Dim row_number As Integer 'row number in target sheet
Dim source_sheet_name As String 'name of the source sheet of the CSV = CSV file name
Dim wb_src As Workbook 'variable for opened CSV source workbook
Dim sht_src As Worksheet 'variable for opened CSV source sheet
Dim sht_csv As Worksheet 'variable for target sheet in ThisWorkbook
With Application
.Calculation = xlCalculationManual
.ScreenUpdating = False
.DisplayAlerts = False
If .StatusBar = False Then appStatus = False Else appStatus = .StatusBar 'show currently processing file in status bar
End With
folder_path = "C:\Folder\SubFolder\" 'here are the files stored
file_name = Dir(folder_path & "*.csv") 'using dir to get file names
row_number = 3 'row number for pasting values
Set sht_csv = ThisWorkbook.Worksheets("2 CSV") 'target sheet for data aggregation
Do While file_name <> ""
Workbooks.Open (folder_path & file_name), UpdateLinks:=False, Local:=True 'open csv file
Set wb_src = Workbooks(file_name) 'assign opened csv file to variable
source_sheet_name = Left(file_name, InStr(file_name, ".") - 1) 'sheet name in csv is the same as the file name
Set sht_src = wb_src.Worksheets(source_sheet_name) 'assign source sheet to variable
If sht_src.Range("C1").Value2 = "OJ_POPIS" Then 'checks if the csv has the correct structure
sht_src.Range("A2:FZ2").Copy 'if so copies desired range
sht_csv.Range("B" & row_number).PasteSpecial 'and pastes it into target worksheet column B
End If
sht_csv.Range("A" & row_number).Value2 = file_name 'writes file name into column A
Application.CutCopyMode = False
wb_src.Close SaveChanges:=False
file_name = Dir() 'fetch next file name
row_number = row_number + 1
'the following lines is what I tried to fix the problem of random excel crashing
Set wb_src = Nothing
Set sht_src = Nothing
Application.StatusBar = "Processing file " & file_name
DoEvents
Application.Wait (Now + TimeValue("0:00:02"))
ThisWorkbook.Save 'save after every loaded file to see which files are causing the problem
Loop
MsgBox "Data from CSV files copied", vbOKOnly
Set sht_csv = Nothing
Application.Calculation = xlCalculationAutomatic
Application.ScreenUpdating = True
Application.DisplayAlerts = True
End Sub
Source CSV files are encoded both in UTF-8 and ANSI (my ACP is ANSI, 1250) and ; delimited.
Group policy restricting macros doesn't apply to me. I can sign my own macros.
What I tried:
Lines of code at the end of the loop
Identifying and deleting files triggering the crash (they have nothing in common, seemingly random, by the time a remove half of them... what is the point)
Simplifying the macro
New workbook
Different machine
VPN On/Off
Thank you for your help!

Answer 1

First thing I'd try is include a proper error handler (not resume next), particularly with x64, and ensure 'Break on all unhandled errors' is selected in Tools / Options / General.
Second thing I'd try is avoid using the clipboard -
With sht_src.Range("A2:FZ2")
sht_cvs.Range("B" & row_number).Resize(.Rows.Count, .Columns.Count).Value = .Value
End With
(no need then to clear CutCopyMode)
Third thing I'd try is don't filter with Dir but something like this -
sFilter = "*.cvs"
file_name = Dir$(, 15) ' without vbDirectory if not getting subfolders
Do While Len(file_name)
If file_name Like sFilter Then
' process file
End If
file_name = Dir$(, 15)
Loop
Fourth thing I'd try is a good cup of coffee!