Expected Behavior

Sitecore.PowerShell.Extensions-5.1.zip will install

Actual Behavior

"An item name cannot start or end with a space"

Node:
"items/core/sitecore/system/Dictionary/PowerShell/T/The data for the dialog is not available Either your server was restarted or the server cache was /{90A4B70F-D65F-477F-A3B0-CF580530DD68}/en/1/xml"

After "was" is a whitespace.

I have tried to set:

setting name="InvalidItemNameChars" value=""
setting name="ItemNameValidation" value="[\s\S]+"
setting name="MaxItemNameLength" value="1000"

Steps to Reproduce the Problem

Sitecore.NET 8.1 (rev. 151207)

Installed:
Sitecore.PowerShell.Extensions-5.0.zip