PDF Application returns html 500 error on IIS

My PDF application displays “Not Working” html 500 error in the production environment using IIS
Export to PDF was also not working but was resolved by installing Visual C++ 2015 x86 on the prod server
thinking it was a rights problem I gave “Everyone” write access to _lib to see if I could affect change but that did not correct the problem
Seems like this is an old problem, what am I missing. Any Ideas on how this can be resolved

With the help of support we were able to solve this by uncommenting extension=php_fileinfo.dll in the php.ini file
it was determined that having a barcode in the pdf layout the app would not run. my production environment is IIS with php 7.033
using powershell and running “php -S localhost:10000” and then running my app in a browser with the url localhost:1000/<myApp>
the error exposed itself in powershell as “undefined function call finfo_open()”
hope that helps

Yo tuve un error similar. Al tratar de abrir un reporte PDF donde se dibujaban líneas con sc_pdf_line daba el error 500, al instalar la extensión php_fileinfo, se soluciono todo y ahora si trabaja correctamente.