Add the check to the right place
MODIFY
WalletWasabi/Blockchain/BlockFilters/IndexBuilderService.cs
WalletWasabi/Blockchain/BlockFilters/IndexBuilderService.cs
@@ -43,6 +43,12 @@ namespace WalletWasabi.Blockchain.BlockFilters
_serviceStatus = NotStarted;
IoHelpers.EnsureContainingDirectoryExists(IndexFilePath);
+
+ // Testing permissions.
+ using (var _ = File.Open(IndexFilePath, FileMode.OpenOrCreate, FileAccess.ReadWrite))
+ {
+ }
+
if (File.Exists(IndexFilePath))
{
if (RpcClient.Network == Network.RegTest)

Add the check to the right place