# Connection Problem after Server mirgating / no Data in the Client App
**URL:** https://talk.remobjects.com/t/connection-problem-after-server-mirgating-no-data-in-the-client-app/25497
**Category:** Relativity Server
**Created:** [October 7, 2021, 1:26pm UTC](https://talk.remobjects.com/t/connection-problem-after-server-mirgating-no-data-in-the-client-app/25497 "2021-10-07T13:26:48Z")
**Posts on this page:** 12
**Page:** 1
### Author:  [@Manfred](https://talk.remobjects.com/u/Manfred)
#### Post date: [October 7, 2021, 1:26pm UTC](https://talk.remobjects.com/t/connection-problem-after-server-mirgating-no-data-in-the-client-app/25497/1 "2021-10-07T13:26:48Z")
Server Installation:
> Relativity Server: v10.0.0.1485
> Data Abstract: v10.0.0.1485
> RemObjects SDK: v10.0.0.1485
> .NET Runtime: v4.0.30319.42000
> Operating System: Unix 5.4.0.84
> Platform: Unix
Cient
> Lazarus
> with FPC 3.2.0 on 2020/12/11 at 16:18:32
> using LCL 2.0.10.0 and LCL 2.0.10.0
>
> ```
> RemObject
> DA Ver.10.0.0.1483
>
> ```
Since i moved my Server to a new host i had to reinstall to whole thing.
My Problem is that i can connect with the Relativity Server Admin and also in the Schema Modeler i see all Tables and can also see the content.
The connection to the Relativity Web Interface is also fine.
I use a LDAP Server for auth and this sees also be fine.
In the log ( Relativity Server Admin ) i see the lines generated with the user info ( this is the code i use )
> | // | log('sn = ’ + session[‘Login.sn’] + ‘’); |
> | --- | --- |
> | | log('uidNumber = ’ + session[‘Login.uidNumber’] + ‘’); |
> | | log(‘ou =’ + session[‘Login.ou’] + ‘’); |
> | | log('gidNumber = ’ + session[‘Login.gidNumber’] + ‘’); |
> | | log('cn = ’ + session[‘[Login.cn](http://Login.cn)’] + ‘’); |
> | | log('uid = ’ + session[‘Login.uid’] + ‘’); |
> | // | log('gecos = ’ + session[‘Login.gecos’] + ‘’); |
> | // | log('departmentNumber = ’ + session[‘Login.departmentNumber’] + ‘’); |
> | | log('description = ’ + session[‘Login.description’] + ‘’); |
> | | log(‘\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_’); |
I don’t know where could be the Problem…
Thanks for any help.
Manfred
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### Author:  [@mh](https://talk.remobjects.com/u/mh)
#### Post date: [October 7, 2021, 1:32pm UTC](https://talk.remobjects.com/t/connection-problem-after-server-mirgating-no-data-in-the-client-app/25497/2 "2021-10-07T13:32:51Z")
Manfred,
what are there exact symptoms/what is the nature of the failure? Does the client cot connect at all? Does the connection fail? does login fail?
I do note from the browser screenshot that you used self-signed/untrusted https/TLS certificate — does the client have the proper trust installed and/or code to verify and trust the specific certificate?
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### Author:  [@Manfred](https://talk.remobjects.com/u/Manfred)
#### Post date: [October 7, 2021, 2:56pm UTC](https://talk.remobjects.com/t/connection-problem-after-server-mirgating-no-data-in-the-client-app/25497/3 "2021-10-07T14:56:00Z")
Hi Marc, the Problem is that i don’t get any error… 😕
Ok i have to admit that i don’t have a error handling in the app.
> Does the client cot connect at all?
Yes, this is also visible in the log ( Relativity Server Admin )
> Does the connection fail? does login fail?
For me this looks like the connection is established:
I was able to find the difference of the 2 Server installations. This error appears from the new Server..
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### Author:  [@mh](https://talk.remobjects.com/u/mh)
#### Post date: [October 7, 2021, 3:20pm UTC](https://talk.remobjects.com/t/connection-problem-after-server-mirgating-no-data-in-the-client-app/25497/4 "2021-10-07T15:20:51Z")
> [@Manfred](#):
>
> Hi Marc, the Problem is that i don’t get any error… 😕
Ok, but what exactly goes wrong/fails?
> [@Manfred](#):
>
> Ok i have to admit that i don’t have a error handling in the app.
Okay, a good place to start might be to handle the prorate OnException (or whatever is there exact name) events on the client, as well as maybe but some try/except bocks around server calls that you think might be failing, and long the Exceptions, if any…
> [@Manfred](#):
>
> 
>
> image762×143 4.95 KB
Now this on em high be more actionable, I’ll have to loop one of my colleagues in, as I’m not 100R sure what this exception means, but it does seem to be one thrown by Remoting SDK (for Delphi, by the name, so in the client side).
@EvgenyK?
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### Author:  [@EvgenyK](https://talk.remobjects.com/u/EvgenyK)
#### Post date: [October 7, 2021, 3:30pm UTC](https://talk.remobjects.com/t/connection-problem-after-server-mirgating-no-data-in-the-client-app/25497/6 "2021-10-07T15:30:08Z")
Hi,
according to error, it’s the DB error - **illegal mix of collations (utf8\_unicode\_ci, COERCIBLE) and (utf8\_general\_ci, COERCIBLE) for operation ‘=’**.
Looks like, you have some DB issue - `utf8_unicode_ci` isn’t equal to `utf8_general_ci`.
check these answers:
- [mysql - Illegal mix of collations (utf8\_unicode\_ci,COERCIBLE) and (utf8\_general\_ci,COERCIBLE) for operation '=' - Stack Overflow](https://stackoverflow.com/questions/18340993/illegal-mix-of-collations-utf8-unicode-ci-coercible-and-utf8-general-ci-coerc)
- [mysql - What's the difference between utf8\_general\_ci and utf8\_unicode\_ci? - Stack Overflow](https://stackoverflow.com/questions/766809/whats-the-difference-between-utf8-general-ci-and-utf8-unicode-ci)
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### Author:  [@Manfred](https://talk.remobjects.com/u/Manfred)
#### Post date: [October 7, 2021, 3:32pm UTC](https://talk.remobjects.com/t/connection-problem-after-server-mirgating-no-data-in-the-client-app/25497/7 "2021-10-07T15:32:39Z")
I try to investigate this on the server…
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### Author:  [@Manfred](https://talk.remobjects.com/u/Manfred)
#### Post date: [October 7, 2021, 3:45pm UTC](https://talk.remobjects.com/t/connection-problem-after-server-mirgating-no-data-in-the-client-app/25497/8 "2021-10-07T15:45:25Z")
The new Server runs not MySQL 😕 It runs MariaDB
OLD:
NEW:
Maybe this could be the Problem… 😒
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### Author:  [@antonk](https://talk.remobjects.com/u/antonk)
#### Post date: [October 7, 2021, 3:51pm UTC](https://talk.remobjects.com/t/connection-problem-after-server-mirgating-no-data-in-the-client-app/25497/9 "2021-10-07T15:51:13Z")
MariaDB is compatible with MySQL
MariaDB project started as fork of the MySQL code and its team try to provide as best compatibility with MySQL as possible. So issue solutions aimed for MySQL should in most cases work for MariaDB too
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### Author:  [@EvgenyK](https://talk.remobjects.com/u/EvgenyK)
#### Post date: [October 7, 2021, 3:51pm UTC](https://talk.remobjects.com/t/connection-problem-after-server-mirgating-no-data-in-the-client-app/25497/10 "2021-10-07T15:51:59Z")
Hi,
you had **latin1** codepage on old server and **utf8mb4** on new one. this can be source of this problem.
check connection string - in delphi drivers, you should specify server charset … .NET drivers may have similar options
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### Author:  [@Manfred](https://talk.remobjects.com/u/Manfred)
#### Post date: [October 7, 2021, 3:53pm UTC](https://talk.remobjects.com/t/connection-problem-after-server-mirgating-no-data-in-the-client-app/25497/11 "2021-10-07T15:53:44Z")
I just did change that on the new server ( Server connection collation: ) to the same setting as the old one.
But the Problem is still there…
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### Author:  [@Manfred](https://talk.remobjects.com/u/Manfred)
#### Post date: [October 7, 2021, 4:32pm UTC](https://talk.remobjects.com/t/connection-problem-after-server-mirgating-no-data-in-the-client-app/25497/15 "2021-10-07T16:32:15Z")
Will alo try to change this: ( Server charset: UTF-8 Unicode (utf8mb4) )
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### Author:  [@Manfred](https://talk.remobjects.com/u/Manfred)
#### Post date: [October 8, 2021, 4:17pm UTC](https://talk.remobjects.com/t/connection-problem-after-server-mirgating-no-data-in-the-client-app/25497/16 "2021-10-08T16:17:57Z")
Hi, the Problem is solved, thanks for your help !!
I “only” had to adapt following setting in the Database.
new:
Have a great weekend. 😁
Shalom
Manfred