Sencha: Cannot satisfy requirements for "ext"

trying to refresh my sencha extjs app and always get this error:

Commands:

sencha app refresh
sencha app upgrade

Always the same error:

[ERR] Cannot satisfy requirements for "ext"!
[ERR]    The following versions cannot be satisfied:
[ERR]       root: ext@5.1.1.451 (No matches!)
[ERR] Cannot resolve package requirements

What can I do?

Sencha Cmd: v6.1.3.42 (with last version 6.2.0 I get this error too)
Core Version 5.0.0
Extjs Version 5.1.1.451

Thanks in advance

This error is occurring because your app is not getting path for ext directory and therefore you are getting error like

[ERR] Cannot satisfy requirements for "ext"! [ERR] Cannot resolve package requirements

to resolve this open this file YourApp\.sencha\workspace\sencha.cfg in your app and in this config file give the path of your ext.dir example : ext.dir=${workspace.dir}/../../../../Ext6.0.3

In case if you don't have ext then you can download from this link.Sencha