diff --git a/bidscoin/bids.py b/bidscoin/bids.py
index 7e7e27d0..ed248999 100644
--- a/bidscoin/bids.py
+++ b/bidscoin/bids.py
@@ -2204,7 +2204,7 @@ def get_bidsvalue(bidsfile: Union[str, Path], bidskey: str, newvalue: str='') ->
     """
 
     # Check input
-    if not bidskey and newvalue:
+    if not bidsfile or (not bidskey and newvalue):
         return bidsfile                         # No fallback
 
     bidspath = Path(bidsfile).parent
diff --git a/bidscoin/plugins/dcm2niix2bids.py b/bidscoin/plugins/dcm2niix2bids.py
index 58f6be85..58785d8f 100644
--- a/bidscoin/plugins/dcm2niix2bids.py
+++ b/bidscoin/plugins/dcm2niix2bids.py
@@ -511,14 +511,14 @@ def bidscoiner_plugin(session: Path, bidsmap: BidsMap, bidsses: Path) -> Union[N
             typeguess, targetguess = metadata.get('BidsGuess') or ['', '']    # BidsGuess: [datatype, filename]
             LOGGER.bcdebug(f"BidsGuess: [{typeguess}, {targetguess}]")
             if typeguess and run.datatype != typeguess:
-                LOGGER.warning(f"The datatype of {target.relative_to(bidsfolder)} does not match with the datatype suggested by dcm2niix: {typeguess}")
+                LOGGER.warning(f"The datatype of {target.relative_to(bidsses)} does not match with the datatype guessed by dcm2niix: {typeguess}")
             elif targetguess and run.bids['suffix'] != bids.get_bidsvalue(targetguess, 'suffix'):
-                LOGGER.warning(f"The suffix of {target.relative_to(bidsfolder)} does not match with the suffix suggested by dcm2niix: {targetguess}")
+                LOGGER.warning(f"The suffix of {target.relative_to(bidsses)} does not match with the suffix guessed by dcm2niix: {targetguess}")
             for entity in ('part', 'inv', 'echo', 'dir'):
                 targetvalue = bids.get_bidsvalue(target, entity)
                 guessvalue  = bids.get_bidsvalue(targetguess, entity)
-                if targetvalue and targetvalue != guessvalue:
-                    LOGGER.warning(f"The '{entity}_{targetvalue}' value in {target.relative_to(bidsfolder)} does not match with the '{entity}_{guessvalue}' value suggested by dcm2niix: {targetguess}")
+                if targetvalue and guessvalue and targetvalue != guessvalue:
+                    LOGGER.warning(f"The '{entity}_{targetvalue}' value in {target.relative_to(bidsses)} does not match with the '{entity}_{guessvalue}' value guessed by dcm2niix: {targetguess}")
 
     # Write the scans_table to disk
     LOGGER.verbose(f"Writing acquisition time data to: {scans_tsv}")