Error opening tif file created by GIMP

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The steps to a pretty straightforward experiment that reproduced the problem are the following:

1. Using GIMP 2.8 open a camera developed jpg file.
   
2. Perform a simple crop (i.e., some editing).
   
3. Create a saved xcf type file.
   
4. Export the image to a tif type file (Compression = "None")
   
5. Close GIMP 2.8
   
6. Start GIMP 2.10
   
7. Verify that the tif type file created above can be opened and then close view
   
8. Open the xcf file previously created by GIMP 2.8
   
9. Export the image to a tif type file (Compression = "None", Advanced options all checked)
   
10. Close view
    
11. Open the tif type file just created by GIMP 2.10 (using GIMP 2.10)
    
12. Error occurs
    

Interesting is that the tif type file created by GIMP 2.8 (Step 4 above), which can be opened using GIMP 2.10, contains practically no metadata.  Whereas the tif type file created by GIMP 2.10 (Step 9 above), which fails to open using GIMP 2.10, contains lots of metadata (i.e., comparable to the camera developed jpg file).  Using ExifTool to examine the metadata in all 3 of the files created in this experiment (2 tif, 1 xcf), none contain an element called "ImageLength".

This observation lead me to try something else which was to use GIMP 2.10 to create (export) a tif type file where the advanced option to create a thumbnail was unchecked (i.e., no thumbnail).  When I subsequently open that tif file using GIMP 2.10 the error regarding invalid "ImageLength" is displayed but the file IS successfully opened.  In that, the problem appears related to the thumbnail.  Therefore, using GIMP 2.10 I opened the camera developed jpg file and exported as tif type as above but with thumbnail.  This worked fine which again brings us back to the point that the GIMP 2.8 xcf still appears to be a factor.