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The problem is with ./includes/common.php and the XOOPS common.php code. xdonations disables using the XOOPS common.php code (see ipnppd.php - line 33).
$xoopsOption['nocommon'] = 1;
The issue is that the xdonations ./includes/common.php uses a subset of the XOOPS common.php file from a previous version of XOOPS - which involks methods in a way that is incompatible with the latest version of Xoops.
Now for the real question: 'Why did the original module designer feel it necessary to bypass the XOOPS common.php file and add a scaled down version?'
If you can find the answer to that question you may be able to determine if you can eliminate the need for the xdonations ./includes/common.php file and just use the current XOOPS version. Otherwise you'll need to modify the xdonations ./includes/common.php file to be similar to the current XOOPS version of that file...