Database failure from Download Template

Hello!
I hope you can help me.
I realized that when trying Download Import File Template
The opportunities module throws the following error: Database failure. Please refer to suitecrm.log for details.

Check the log but it just throws this at me:

[31112][1][FATAL] Exception in Controller: Database failure. Please refer to suitecrm.log for details.

Maybe something similar happened to him?

*** The Code has not been modified at all **
Thank you

Do you have anything on your php error log. I believe if database failure, It always log into suitecrm.log file.
Can you also specify which version fo SuiteCRM you are using along with server information?

Thanks for answering
Sure the logs are these:

Thu Jul 16 20:47:17 2020 [16845][1][DEBUG] Hook called: ::server_round_trip
Thu Jul 16 20:47:17 2020 [16845][1][DEBUG] Calling MySQLi::disconnect()
Thu Jul 16 20:47:17 2020 [16845][1][FATAL] Exception handling in /opt/suitecrm/include/MVC/Controller/SugarController.php:400
Thu Jul 16 20:47:17 2020 [16845][1][FATAL] Exception in Controller: Falla de base de datos. Consulte suitecrm.log para obtener más información.
Thu Jul 16 20:47:17 2020 [16845][1][FATAL] backtrace:
#0 /opt/suitecrm/include/database/DBManager.php(353): sugar_die(‘Falla de base d…’)
#1 /opt/suitecrm/include/database/DBManager.php(328): DBManager->registerError(‘Error exportand…’, ‘Error exportand…’, true)
#2 /opt/suitecrm/include/database/MysqliManager.php(179): DBManager->checkError(‘Error exportand…’, true)
#3 /opt/suitecrm/include/database/MysqlManager.php(285): MysqliManager->query(‘SELECT\n …’, true, ‘Error exportand…’)
#4 /opt/suitecrm/include/export_utils.php(189): MysqlManager->limitQuery(‘SELECT\n …’, 0, 5, true, ‘Error exportand…’)
#5 /opt/suitecrm/include/export_utils.php(568): export(‘Opportunities’, NULL, false, true)
#6 /opt/suitecrm/export.php(64): exportSample(‘Opportunities’)
#7 /opt/suitecrm/include/MVC/Controller/SugarController.php(1020): require_once(’/opt/suitecrm/e…’)
#8 /opt/suitecrm/include/MVC/Controller/SugarController.php(468): SugarController->handleEntryPoint()
#9 /opt/suitecrm/include/MVC/Controller/SugarController.php(373): SugarController->process()
#10 /opt/suitecrm/include/MVC/SugarApplication.php(113): SugarController->execute()
#11 /opt/suitecrm/index.php(52): SugarApplication->execute()
#12 {main}
Thu Jul 16 20:47:17 2020 [16845][1][DEBUG] Hook called: Opportunities::handle_exception
Thu Jul 16 20:47:17 2020 [16845][1][DEBUG] Including module specific hook file for custom/modules/Opportunities
Thu Jul 16 20:47:20 2020 [1225][-none-][DEBUG] current_language is: en_us
Thu Jul 16 20:47:20 2020 [1225][-none-][DEBUG] Found cache backend SugarCacheAPC
Thu Jul 16 20:47:20 2020 [1225][-none-][DEBUG] Found cache backend SugarCacheFile
Thu Jul 16 20:47:20 2020 [1225][-none-][DEBUG] Found cache backend SugarCacheMemcache
Thu Jul 16 20:47:20 2020 [1225][-none-][DEBUG] Found cache backend SugarCacheMemcached
Thu Jul 16 20:47:20 2020 [1225][-none-][DEBUG] Found cache backend SugarCacheMemory
Thu Jul 16 20:47:20 2020 [1225][-none-][DEBUG] Using cache backend SugarCacheMemory, since 999 is less than 1000
Thu Jul 16 20:47:20 2020 [1225][-none-][DEBUG] Found cache backend SugarCacheRedis
Thu Jul 16 20:47:20 2020 [1225][-none-][DEBUG] Found cache backend SugarCacheWincache
Thu Jul 16 20:47:20 2020 [1225][-none-][DEBUG] Found cache backend SugarCacheZend
Thu Jul 16 20:47:20 2020 [1225][-none-][DEBUG] Found cache backend SugarCachesMash

Really,do not know what happens, i have not made any modification in the database or code