Layout file corrupted, no drawing tools work


Suddenly dimension tool (as well as other drawing tools) quit working. Rebooted and same problem. Suspect file is somehow corrupt. Was able to use “Timemachine” to open earlier file that works. This is the second time this has occurred and had a lot invested in the drawings. Would like to know how to fix or avoid problem. I am running Layout 2017 on Mac Yosemite on older Power Book. Thanks