update to 2.2.8, works on php 5.6 but doen't on 7.0. Why?

[okulyth]

Hello. I am busy updating an old clients website to the latest core version 2.2.8 (from an unmaintained 1.11.13 version). Which took quite a while in order to get all functionality to work again.

Now it works, under php 5.6. But when I switch to php 7.0, it does not, only a white window appears.

this is the list of Modules I am using on the system:

system AdminSearch 1.0.4 Installed
Captcha 1 Installed
CGContentUtils 2.2.3 Installed
CGExtensions 1.61.3 Installed
CGGoogleMaps2 1.1.1 Installed
CGJobMgr 1.3.6 Installed
CGSimpleSmarty 2.2 Installed
CGSnapshot 1.3 Installed
system CMSContentManager 1.1.6 Installed
deprecated CMSMailer 6.2.14 Installed
system DesignManager 1.1.4 Installed
system FileManager 1.6.7 Installed
system FilePicker 1.0.3 Installed
FormBuilder 0.8.1.6 Installed
Gallery 2.3.2 Installed
GoogleMaps 0.2.1 Installed
JQueryTools 1.4.0.3 Installed
system deprecated MenuManager Not installed
system MicroTiny 2.2.2 Installed
MleCMS 2.0-beta1 Installed
system ModuleManager 2.1.4 Installed
system Navigator 1.0.9 Installed
system News 2.51.4 Installed
system Search 1.51.5 Installed
SEOTools2 1.2.1 Installed
Showtime2 3.5.4 Installed
XMLMadeSimple Not installed

Which one of those might be the culprit that makes the system bomb out? Thank you in advance for the help.

[DIGI3]

Your error log would give a lot more information, but if that doesn't help I would start with the modules that haven't been updated in a while. Rename their folders to temporarily disable them.

[paulbaker]

Pretty sure SEOTools2 doesn't work with v2 so it might be that:
http://dev.cmsmadesimple.org/projects/seotools2