The attribute drawooo:display is missing in file OpenDocument-v1.3+libreoffice-schema.rng. Thus validation fails for documents which contain this attribute. This affects especially unit tests with 'saveAndReload' method. Such unit tests have now the 'SkipValidation' workaround. The attribute was introduced with https://git.libreoffice.org/core/commit/33ef17ed7207b82d8e6fe1fa4ddaec676092d0f1
Regina Henschel committed a patch related to this issue. It has been pushed to "master": https://git.libreoffice.org/core/commit/1d2830b936d02ed0882d9cc1234ddafb3bb7e8dd tdf#155271 add drawooo:display to libreoffice-schema It will be available in 7.6.0. The patch should be included in the daily builds available at https://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: https://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.