Could not save the list changes to the server

Question

I have an External List in SharePoint 2013. I am trying to create a new Edit Form in SharePoint Designer but unfortunately it is throwing Could not save the list changes to the server error instead of letting me create new form.

I have tried various approaches that I found in internet which are as under, but none of them helped in my case. Here are the attempts that I made

1. Delete External List, Delete External Content Type and recreate both External Content Type and External List.
2. Delete both ECT and EL from Recycle Bin, Second Stage Recycle Bin and recreate.
3. Recreate both ECT and EL with completely new name not used in past.
4. Cleared cache, by deleting files in location C:\Users\MyUserName\AppData\Local\Microsoft\Website Cache
5. Restarted my computer

I don't have access to Central Admin and the logon to the machine on which SharePoint Server is installed. I am stuck in this issue for almost three days and have no clue what to do next. Thanks in advance for reading my issue and for lending a helping mind.

Answer 1

After lots of hits and trials, following two approaches helped me resolve the issues.

1. The column titles in SQL Server had symbols like $, % and _. I removed these symbols and just included plain texts in the column titles.
2. The SQL Server table had more than 20k rows. I deleted all rows and just kept 1 row. Then I tried to create new Edit Form in SharePoint designer.

Viola! It did create new Edit Form and allowed me to save the External List. Once I am done with customizing my new Edit Form, I did delete all rows (final 1 row) from SQL Server table and loaded all the rows back.

Cheers!