Cannot grunt browserify

[francesco-gallo]

Launching the command grunt browserify I get the error

Running "browserify:development" (browserify) task
[BABEL] Note: The code generator has deoptimised the styling of /home/francesco/Projects/BIMsurfer/viewer/cesium/ThirdParty/Workers/draco_decoder.js as it exceeds the max of 500KB.
>> Error: Can't walk dependency graph: Cannot find module '2' from '/home/francesco/Projects/BIMsurfer/viewer/cesium/ThirdParty/protobuf-minimal.js'
>>     required by /home/francesco/Projects/BIMsurfer/viewer/cesium/ThirdParty/protobuf-minimal.js
Warning: Error running grunt-browserify. Use --force to continue.

Aborted due to warnings.