Error Not a PDF file though my input is pdf file

[info] running org.allenai.pdffigures2.FigureExtractorVisualizationCli ./input/Dynamic_Memory_Network_Sochar_QA.pdf
Error: File ./input/Dynamic_Memory_Network_Sochar_QA.pdf is not a PDF file
figure-extractor-visualize

I am getting the error above. Entire Console Output Below

[info] Loading settings for project pdffigures2-master-build from plugins.sbt ...
[info] Loading project definition from /Data/tanik/Multi-modalQA/pdffigures2-master/project
[info] Loading settings for project root from build.sbt ...
[info] Set current project to pdffigures2 (in build file:/Data/tanik/Multi-modalQA/pdffigures2-master/)
[warn] Multiple main classes detected. Run 'show discoveredMainClasses' to see the list
[info] running org.allenai.pdffigures2.FigureExtractorVisualizationCli ./input/Dynamic_Memory_Network_Sochar_QA.pdf
Error: File ./input/Dynamic_Memory_Network_Sochar_QA.pdf is not a PDF file
figure-extractor-visualize
Usage: figure-extractor-visualize [options]

input PDF file
-s, --show-steps Show all intermediate steps
-g, --show-graphic-clustering 0s
Show graphical elements found and how they were clustered
-x, --show-cleaned-figure-regions
Shows figure regions after being post-processed using the rasterized PDF at the given DPI
-e, --show-extractions Show the bounding boxes of the text and graphics that were extracted
-r, --show-regions Show the different regions the PDF was broken into
-c, --show-captions Show the location of the captions
-t, --show-sections Show the location of sections and paragraphs
-d, --display-dpi
DPI to display figures at (default 55)
-p, --pages Pages to extract from (defaults to all), 1 is the first page

Exception: sbt.TrapExitSecurityException thrown from the UncaughtExceptionHandler in thread "run-main-0"
[error] Nonzero exit code: 1
[error] (Compile / runMain) Nonzero exit code: 1
[error] Total time: 1 s, completed 18-Mar-2022, 12:53:44 PM

Any idea how to resolve the issue?