You are trying to set the bootable flag on a logical partition. The bootable flag is generally only useful on primary partitions, so setting it on logical partitions is normally discouraged. Some BIOS versions are known to fail to boot if there is no bootable primary partition.
Tettaɛraḍeḍ ad tesbaduḍ anay aziraz ɣef uḥric ameẓẓul. Anay aziraz deg tuget yelha kan ɣef yiḥricen igejdanen, ɣef waya ur d-yettuwelleh ara ad yettusbadu ɣef yiḥricen imeẓẓulen. Kra n yileqman n BIOS ttwassnen s tuccḍa-nsen deg usenker ma yili ulac aḥric agejdan aziraz.