Unable to mount and failed to install custom ROM in Droid XT912

I have a Droid Razr XT912 which was bricked but now recovered after some effort followed from XDA. Now I'm trying to install a new custom ROM to my device with Safestrap, but it's giving me a message about failure on every action, such as failed to create backup, failed on wipe and failed to install. (Click image to enlarge) " class="img-fluid rounded" style="max-width: 100%; height: auto; margin: 10px 0;" loading="lazy"> Can anybody tell me what should I do?