I wrote yesterday "it is non-sense for users to udpate the module for customizing its templates."
I also write today "it is non-sense for module developpers to udpate the module for comfirming its templates."
First, install altsys.
Then, insert 2 lines into mainfile.php like this:
if (!isset($xoopsOption['nocommon'])) {
include XOOPS_ROOT_PATH."/include/common.php";
$tplsadmin_autoupdate_dirnames = array( 'piCal' ) ;
include XOOPS_TRUST_PATH."/libs/altsys/include/autoupdate_from_module.inc.php" ;
}