MikTex - pdflatex does not compile - initexmf.exe

MiKTeX: 2.9.7440
GitInfo: af89c1b / 2020-05-20 09:20:28
OS: Windows 10 Pro, 64-bit, build 10586

1. Miktex deinstalled and reinstalled after cleaning all paths (and I searched the registry)
2. Tried different settings (each time first deinstall –> then clean install): windows 64 installation, windows 32 installation, local user, all user, admin, no admin, update/no update …
3. pdflatex –> build package generates error: C:Usersxxx xxxAppDataLocalProgramsMiKTeX 2.9miktexbinx64initexmf.exe did not succeed; exitCode: 1"
4. I also tried Miktex as a portable App and got the same results.

A week ago I had no problems. I just wonder if a Windows Update causes the trouble.

This is now the content of the log file (pdflatex.log):

The log file hopefully contains the information to get MiKTeX going again:

  C:Usersxxx xxxAppDataLocalMiKTeX2.9miktexloginitexmf.log

2020-06-26 16:03:13,851+0200 FATAL pdflatex.core - The memory dump file could not be found.
2020-06-26 16:03:13,851+0200 FATAL pdflatex.core - Data: fileName="pdflatex.fmt"
2020-06-26 16:03:13,851+0200 FATAL pdflatex.core - Source: LibrariesMiKTeXTeXAndFriendstexmfapp.cpp:692
2020-06-26 16:03:13,851+0200 FATAL pdflatex - The memory dump file could not be found.
2020-06-26 16:03:13,851+0200 FATAL pdflatex - Info: fileName="pdflatex.fmt"
2020-06-26 16:03:13,851+0200 FATAL pdflatex - Source: LibrariesMiKTeXTeXAndFriendstexmfapp.cpp
2020-06-26 16:03:13,851+0200 FATAL pdflatex - Line: 692
2020-06-26 16:03:13,851+0200 INFO  pdflatex - this process (14480) finishes with exit code 1
2020-06-26 16:44:00,069+0200 INFO  pdflatex - this process (5508) started by 'texmaker' with command line: pdflatex -synctex=1 -interaction=nonstopmode test.tex
2020-06-26 16:44:00,079+0200 INFO  pdflatex - allowing known shell commands
2020-06-26 16:44:00,079+0200 INFO  pdflatex - enabling input (output) from (to) processes
2020-06-26 16:44:00,114+0200 INFO  pdflatex - going to create file: pdflatex.fmt
2020-06-26 16:44:00,149+0200 INFO  pdflatex.core - start process: initexmf --dump-by-name=pdflatex --engine=pdftex
2020-06-26 16:44:02,816+0200 ERROR pdflatex - C:Usersxxx xxxAppDataLocalProgramsMiKTeX 2.9miktexbininitexmf.exe did not succeed; exitCode: 1
2020-06-26 16:44:02,816+0200 ERROR pdflatex - output:
2020-06-26 16:44:02,816+0200 ERROR pdflatex - 
Sorry, but "MiKTeX Configuration Utility" did not succeed.

The log file hopefully contains the information to get MiKTeX going again:

  C:Usersxxx xxxAppDataLocalMiKTeX2.9miktexloginitexmf.log

2020-06-26 16:44:02,816+0200 FATAL pdflatex.core - The memory dump file could not be found.
2020-06-26 16:44:02,816+0200 FATAL pdflatex.core - Data: fileName="pdflatex.fmt"
2020-06-26 16:44:02,816+0200 FATAL pdflatex.core - Source: LibrariesMiKTeXTeXAndFriendstexmfapp.cpp:692
2020-06-26 16:44:02,816+0200 FATAL pdflatex - The memory dump file could not be found.
2020-06-26 16:44:02,816+0200 FATAL pdflatex - Info: fileName="pdflatex.fmt"
2020-06-26 16:44:02,816+0200 FATAL pdflatex - Source: LibrariesMiKTeXTeXAndFriendstexmfapp.cpp
2020-06-26 16:44:02,816+0200 FATAL pdflatex - Line: 692
2020-06-26 16:44:02,817+0200 INFO  pdflatex - this process (5508) finishes with exit code 1
2020-06-26 17:14:23,162+0200 INFO  pdflatex - this process (14576) started by 'texmaker' with command line: pdflatex -synctex=1 -interaction=nonstopmode test.tex
2020-06-26 17:14:23,172+0200 INFO  pdflatex - allowing known shell commands
2020-06-26 17:14:23,172+0200 INFO  pdflatex - enabling input (output) from (to) processes
2020-06-26 17:14:23,206+0200 INFO  pdflatex - going to create file: pdflatex.fmt
2020-06-26 17:14:23,238+0200 INFO  pdflatex.core - start process: initexmf --dump-by-name=pdflatex --engine=pdftex
2020-06-26 17:14:26,002+0200 ERROR pdflatex - C:Usersxxx xxxAppDataLocalProgramsMiKTeX 2.9miktexbininitexmf.exe did not succeed; exitCode: 1
2020-06-26 17:14:26,002+0200 ERROR pdflatex - output:
2020-06-26 17:14:26,002+0200 ERROR pdflatex - 
Sorry, but "MiKTeX Configuration Utility" did not succeed.

The log file hopefully contains the information to get MiKTeX going again:

  C:Usersxxx xxxAppDataLocalMiKTeX2.9miktexloginitexmf.log

2020-06-26 17:14:26,002+0200 FATAL pdflatex.core - The memory dump file could not be found.
2020-06-26 17:14:26,002+0200 FATAL pdflatex.core - Data: fileName="pdflatex.fmt"
2020-06-26 17:14:26,002+0200 FATAL pdflatex.core - Source: LibrariesMiKTeXTeXAndFriendstexmfapp.cpp:692
2020-06-26 17:14:26,002+0200 FATAL pdflatex - The memory dump file could not be found.
2020-06-26 17:14:26,002+0200 FATAL pdflatex - Info: fileName="pdflatex.fmt"
2020-06-26 17:14:26,002+0200 FATAL pdflatex - Source: LibrariesMiKTeXTeXAndFriendstexmfapp.cpp
2020-06-26 17:14:26,003+0200 FATAL pdflatex - Line: 692
2020-06-26 17:14:26,003+0200 INFO  pdflatex - this process (14576) finishes with exit code 1