New Post: Failure to Create User Profile Service Application and I have no clue why

I can only assume that the issue was with the My Sites site collection template ID.

I stumbled across this error when the template it was set to STS#0 on this section where SPSMSITEHOST#0 should be:

<WebApplication type="MySiteHost" name="MySite Host" applicationPool="MySites" url="http://mysites" port="80" UseHostHeader="true" AddURLToLocalIntranetZone="true" GrantCurrentUserFullControl="true" useClaims="true" useBasicAuthentication="false" useOnlineWebPartCatalog="false">
      <Database>
        <Name>Content_MySites</Name>
        <DBServer />
        <DBAlias Create="false" DBInstance="SERVER\INSTANCE" DBPort="" />
      </Database>
      <ManagedPaths>
        <ManagedPath relativeUrl="personal" explicit="false" />
      </ManagedPaths>
      <SiteCollections>
        <SiteCollection siteUrl="http://mysites" HostNamedSiteCollection="false" Owner="dev\sp2013admin" Name="My Sites" Description="My Sites" SearchUrl="http://localhost/search" CustomTemplate="false" Template="SPSMSITEHOST#0" LCID="1033" Locale="en-us" Time24="false" />
      </SiteCollections>
    </WebApplication>

Hope this helps.