[TYPO3] front end user registration: blank page when choosing alternative language

[Robert Markula]

Franz Holzinger wrote:
> Which settings code/flexform plugin do you use?

Hi Franz,
I'm using "Create" and "Not set" (both show this error) with flexforms 
enabled.

Cheers,
Ro

PS: My TS config looks like this:
### SNIP start ###
# Front End User Registration
plugin.tx_srfeuserregister_pi1 {
   file.templateFile = fileadmin/system/templates/tx_srfeuserregister.html
   enableHTMLMail = 0
   email = info at domain.com
   siteName = info at domain.com
   formFields = 
first_name,last_name,email,address,zip,city,static_info_country,telephone,language,company,username,password
   requiredFields = 
first_name,last_name,email,address,zip,city,static_info_country,telephone,language,company,username,password
   onChangeCountryAttribute =
   enablePreviewRegister = 1
   enablePreviewEdit = 1
   enableAdminReview = 1
   enableEmailConfirmation = 1

   enableEmailOnApprove = 1
   enableEmailOnRefuse = 1
   enableEmailOnRegister = 0
   enableEmailOnUpdate = 1
   enableEmailOnDelete = 1
   enableAdminNotifyConfirmation = 1
   enableAdminNotifyOnApprove = 1
   enableAdminNotifyOnRefuse = 1
   enableAdminNotifyOnRegister = 1
   enableAdminNotifyOnUpdate = 1
   enableAdminNotifyOnDelete = 1

   passwordAtLeast = 4
   usernameAtLeast = 2
   useShortUrls = 1

   pid = 263
   registerPID = 311
   editPID = 312
   confirmPID = 313
   loginPID = 251
   userGroupAfterConfirmation =
}
### SNIP end ###