fix combined pdf

lib/submissions/generate_combined_attachment.rb

@@ -23,15 +23,9 @@ module Submissions
           **Submissions::GenerateResultAttachments.build_signing_params(submitter, pkcs, tsa_url)
         }
 
-        begin
-          pdf.sign(io, **sign_params)
-        rescue HexaPDF::MalformedPDFError => e
-          Rollbar.error(e) if defined?(Rollbar)
-
-          pdf.sign(io, write_options: { incremental: false }, **sign_params)
-        end
+        sign_pdf(io, pdf, sign_params)
       else
-        pdf.write(io, incremental: true, validate: false)
+        pdf.write(io, incremental: true, validate: true)
       end
 
       Submissions::GenerateResultAttachments.maybe_enable_ltv(io, sign_params)
@@ -45,6 +39,20 @@ module Submissions
       )
     end
 
+    def sign_pdf(io, pdf, sign_params)
+      pdf.sign(io, **sign_params)
+    rescue HexaPDF::MalformedPDFError => e
+      Rollbar.error(e) if defined?(Rollbar)
+
+      pdf.sign(io, write_options: { incremental: false }, **sign_params)
+    rescue HexaPDF::Error => e
+      Rollbar.error(e) if defined?(Rollbar)
+
+      pdf.validate(auto_correct: true)
+
+      pdf.sign(io, write_options: { validate: false }, **sign_params)
+    end
+
     def build_combined_pdf(submitter)
       pdfs_index = Submissions::GenerateResultAttachments.generate_pdfs(submitter)