Android Question 'The system cannot find the specified file' error after upgrade to version 12

Hello,

After many years I have now started programming again. I have upgraded B4A to version 12.

When compiling my program, I now unfortunately get the following error message:
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B4A Version: 12.00
Parsing code. (0.06s)
Java Version: 11
Building folders structure. (0.01s)
Compiling code. (0.12s)
Compiling layouts code. (0.02s)
Organizing libraries. (0.00s)
(AndroidX SDK)
Compiling resources (0.16s)
Linking resources (0.28s)
Compiling generated Java code. (0.01s)
Finding libraries that need to be dexed. (0.00s)
Dex code (0.41s)
Dex merge (1.02s)
Copying libraries resources (0.06s)
ZipAlign file. (0.04s)
Signing package file (private key). (0.54s)
Installing file to device. Error
Das System kann die angegebene Datei nicht finden
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Any idea?
Thanks a lot for your help....