For my 1st gen moto X , I was able to resolve the issue by:

1. clearing up disk space
2. updating all apps
3. boot through optimization (~130 apps)
4. clear cache (2.75MB remains)
5. power off (shut down)
6. boot through optimization (2 apps)
7. clear cache (3.5MB -> 2.84MB remains)
8. power off (shut down)
9. boot -- No Optimization!

I was at 500MB of free space and increased that to 5GB by deleting photos and downloads.

A few other ideas from around the net:

• Clear cache
• Clear up diskspace
• Boot into safemode http://allaboutmotog.com/moto-g-how-to-guide/how-to-use-moto-g-safe-mode-applies-to-moto-x-and-moto-e-safe-mode-as-well/

For my 1st gen moto X , I was able to resolve the issue by:

1. clearing up disk space
2. updating all apps
3. boot through optimization (~130 apps)
4. clear cache (2.75MB remains)
5. power off (shut down)
6. boot through optimization (2 apps)
7. clear cache (3.5MB -> 2.84MB remains)
8. power off (shut down)
9. boot -- No Optimization!

I was at 500MB of free space and increased that to 5GB by deleting photos and downloads.

A few other ideas from around the net:

• Clear cache
• Clear up diskspace
• Boot into safemode How to use Moto G safe mode (applies to Moto X and Moto E safe mode as well )? | Moto G Phone Guide