I attempted to index some image JPG files into Solr example collection, “techproducts” by using the following command on Windows 10 command line prompt:
java -Dc=techproducts -Dauto -classpath serversolr-webappwebappWEB-INFlibsolr-core-9.4.0.jar org.apache.solr.cli.SimplePostTool exampleexampledocs*

I am using Solr-9.4.0.

Three image files are indexed successfully but one JPG file got some error message as follows:
POSTing file SSpan_onSites.jpg (application/octet-stream) to [base]/extract SimplePostTool: WARNING: Solr returned an error #400 (Bad Request) for url: http://localhost:8983/solr/techproducts/update/extract?resource.name=C%3A%5CSolr%5Csolr-9.4.0%5Cexample%5Cexampledocs%5CSSpan_onSites.jpg&literal.id=C%3A%5CSolr%5Csolr-9.4.0%5Cexample%5Cexampledocs%5CSSpan_onSites.jpg SimplePostTool: WARNING: Response: { "responseHeader":{ "status":400, "QTime":25 }, "error":{ "metadata":["error-class","org.apache.solr.common.SolrException","root-error-class","org.apache.solr.common.SolrException"], "msg":"ERROR: [doc=C:\Solr\solr-9.4.0\example\exampledocs\SSpan_onSites.jpg] Error adding field 'last_modified'='2018-07-13T19:59:54' msg=Invalid Date String:'2018-07-13T19:59:54'", "code":400 } } SimplePostTool: WARNING: IOException while reading response: java.io.IOException: Server returned HTTP response code: 400 for URL: http://localhost:8983/solr/techproducts/update/extract?resource.name=C%3A%5CSolr%5Csolr-9.4.0%5Cexample%5Cexampledocs%5CSSpan_onSites.jpg&literal.id=C%3A%5CSolr%5Csolr-9.4.0%5Cexample%5Cexampledocs%5CSSpan_onSites.jpg

I don’t understand why some of my image JPG files can be indexed but only one image JPG file can not be indexed and caused this error message. I used the default schema of “techproducts” which should enable the extraction module for RequestHandler “/update/extract”. I can see these three indexed image files are handled by “/update/extract”:
POSTing file Nav_bar.jpg (application/octet-stream) to [base]/extract

I have checked my four image files: all have “Date modified: xxxx” attributes. If the field, “last_modified” was not defined properly, it should have impacts on all image files. Why does only one image file have such error? It is really strange. Does someone come across the similar error message before? Thanks in advance.

I tried to index the image files with Solr 9.4.0 but got some error message regarding field “last_modified”. I expect that all image JPG files should be indexed successfully.