Contao

I wanted set a CE gallery but with my own template. I prepare gallery_oliwa.tpl template and upload to /template/oliwia folder where are the rest templates related to my theme.
When I created CE gallery I was able to see my own template on "Gallery template" list. After "Save" everything seems to be fine in FE and in BE. Bu when I press "Save and close" I receive this error:

Fatal error: Uncaught exception Exception with message Could not find template file "gallery_oliwa" thrown in /home/qrczak/public_html/mypage/system/libraries/Controller.php on line 109
#0 /home/qrczak/public_html/mypage/system/libraries/Template.php(142): Controller->getTemplate('gallery_oliwa')
#1 /home/qrczak/public_html/mypage/system/modules/frontend/FrontendTemplate.php(49): Template->parse()
#2 /home/qrczak/public_html/mypage/system/modules/frontend/ContentGallery.php(285): FrontendTemplate->parse()
#3 /home/qrczak/public_html/mypage/system/modules/frontend/ContentElement.php(128): ContentGallery->compile()
#4 /home/qrczak/public_html/mypage/system/modules/frontend/ContentGallery.php(74): ContentElement->generate()
#5 /home/qrczak/public_html/mypage/system/libraries/Controller.php(415): ContentGallery->generate()
#6 /home/qrczak/public_html/mypage/system/modules/backend/dca/tl_content.php(781): Controller->getContentElement('142')
#7 /home/qrczak/public_html/mypage/system/drivers/DC_Table.php(3478): tl_content->addCteType(Array)
#8 /home/qrczak/public_html/mypage/system/drivers/DC_Table.php(345): DC_Table->parentView()
#9 /home/qrczak/public_html/mypage/system/modules/backend/Backend.php(234): DC_Table->showAll()
#10 /home/qrczak/public_html/mypage/contao/main.php(101): Backend->getBackendModule('article')
#11 /home/qrczak/public_html/mypage/contao/main.php(297): Main->run()
#12 {main}

It's mean I can't get list of CE elements of this article. The system says to me that Could not find template file "gallery_oliwa" but this template was on the list and it works in FE. But if I copy my template to /system/modules/frontend/templates error disappeared.
I checked this on two installations.